The Peter Attia Drive - #239 ‒ The science of strength, muscle, and training for longevity

00:00:00.000 Hey, everyone. Welcome to the drive podcast. I'm your host, Peter Atiyah. This podcast,

00:00:15.500 my website, and my weekly newsletter all focus on the goal of translating the science of longevity

00:00:19.820 into something accessible for everyone. Our goal is to provide the best content in health and

00:00:24.780 wellness, full stop. And we've assembled a great team of analysts to make this happen.

00:00:28.900 If you enjoy this podcast, we've created a membership program that brings you far more

00:00:33.320 in-depth content. If you want to take your knowledge of the space to the next level at

00:00:37.340 the end of this episode, I'll explain what those benefits are. Or if you want to learn more now,

00:00:41.760 head over to peteratiyahmd.com forward slash subscribe. Now, without further delay,

00:00:47.780 here's today's episode. My guest this week is Andy Galpin. Andy is a professor of kinesiology

00:00:54.560 at California State University Fullerton, where his biochemistry and molecular exercise physiology

00:00:59.600 lab researches the acute responses of chronic adaptations of skeletal muscle to high intensity,

00:01:04.840 power, or force and fatiguing exercise. Andy's research spans adaptations from whole muscle to

00:01:12.260 cellular level changes, which he's applied to his work with professional athletes for more than about

00:01:16.220 15 years. In this episode, we focus our conversation specifically around one of the four pillars of

00:01:22.100 exercise, which is strength. And we focus a lot of the conversation around muscle. Now,

00:01:27.340 at the beginning of this episode, which I really enjoyed, we talk pretty technically. I'm not going

00:01:32.920 to hide that. We get into the anatomy, microanatomy, and physiology of the muscle. And I think it's

00:01:38.680 important because I do think that this is a subject matter that I talk about a lot. I think a lot of

00:01:44.080 podcasters talk about this stuff a lot. But I think it's important to really understand some of the

00:01:49.840 details. I mean, something as simple as what does it mean to undergo hypertrophy? What does it mean

00:01:55.320 for a muscle to get bigger? What exactly is getting bigger? What is the difference between power,

00:02:02.220 strength, speed, and hypertrophy? And how do those differences phenotypically relate to what's

00:02:07.700 happening at the cellular level or at the functional unit level? So we talk about all of those things. We

00:02:12.700 talk about muscles and their energy sources. We talk about the importance of protein on muscle

00:02:17.280 synthesis. We talk about the various types of muscle fibers, which is actually something where I

00:02:21.820 probably learned more in this discussion on that particular topic than anything else that Andy and

00:02:26.440 I spoke about. We end the conversation looking at a case study of how Andy would create a program

00:02:31.060 for an untrained person who just started to do a few hours of cardio, but wanted to spend three days

00:02:37.100 a week building strength with a focus on building strength for longevity. Now, we did this because

00:02:41.860 that approach was so popular in some of our previous podcasts. I think listeners really like hearing

00:02:47.480 how we take kind of this high fluid science and now bring it back down to how can you apply this to

00:02:53.440 your life? One final point I'll make here is that as is sort of common with me, I go into these podcasts

00:02:59.280 with a long list of topics I want to explore and sometimes I don't get close to it. And that was

00:03:05.160 certainly the case here. Andy and I barely scratched the surface of what I wanted to cover. So this will

00:03:11.860 be part one of two because I'll be sitting down again with Andy shortly to do the second part of

00:03:18.140 this. So without further delay, please enjoy my conversation with Andy Galpin.

00:03:27.940 Well, Andy, it's wonderful to see you here on video. We were supposed to do this in person,

00:03:33.400 but we got a good laugh as to why that didn't pan out, but that's okay. Perhaps there'll be an

00:03:37.980 in-person chance the next time. Yeah, I'm excited to be here this way. It would have been more

00:03:42.280 enjoyable in person, but we'll make it work. You know, I've wanted to speak with you for quite a

00:03:47.080 while and I think listeners to this podcast are not strangers to the idea of how much of an emphasis

00:03:51.320 I place on exercise. I've said it many times before. I'll continue to reiterate it until the data

00:03:56.160 suggests. Otherwise, that there's really no more potent tool to improve longevity, meaning extending

00:04:04.420 the length of life and improving the quality of life than exercise. And that includes nutrition,

00:04:09.400 that includes sleep, and that includes the entire pharmacopoeia of medication, supplements, drugs,

00:04:14.220 hormones, et cetera. So it's probably for that reason that I would say that exercise makes up a

00:04:19.600 disproportionate amount of the content on our podcast. And of course, within exercise, I tend to

00:04:24.960 divide it really down into these different pillars of strength, stability, and cardiorespiratory fitness,

00:04:30.800 which of course then gets further subdivided by the metabolic state and energy state of it.

00:04:35.060 And of course, what we're going to probably talk a lot about today is strength, but also all of the

00:04:38.620 things that kind of stem from that, like hypertrophy and various things like that, which I think are

00:04:42.360 of huge interest to people. But maybe for folks who don't know you, can you give us a sense of

00:04:47.740 your path, you know, frankly, out of high school, college, like, you know, what was your

00:04:52.100 athletic background and what made this be something that you have dedicated all of your time to?

00:04:57.180 Sure. I guess initially I need to state a conflict of interest, which is I'm an exercise scientist.

00:05:01.860 So if you want to start giving more credit to exercise for longevity and wellness, like

00:05:05.440 I cannot be a little more biased into that lane, especially within exercise science strength training.

00:05:11.980 So I've been waiting for 30 years for this to happen in the field. So now I get to prove that all

00:05:16.240 my preconceived notions are actually holding true. I will refuse to change despite what you said.

00:05:20.880 I will refuse to change despite what the data suggests. For real, I grew up in a very small

00:05:24.900 town in Southwest Washington. So I played everything in high school, football, basketball, baseball,

00:05:31.020 track and field, the whole thing. I went to a small school in Oregon where I played college football

00:05:35.640 and got my undergraduate degree in exercise science. And then after that, I made some stops in Arizona

00:05:41.000 and worked at a facility training professional athletes. Went back and got my master's degree

00:05:46.020 and human movement sciences, which is just a other fancy way of saying kinesiology or exercise

00:05:51.660 science. And then got my PhD in human bioenergetics. So in 2011, I got that, came out here to California,

00:05:59.940 and I've been working at Cal State Fullerton ever since. So I've been for a while now, the director

00:06:04.780 for the Center for Sport Performance there, as well as my lab, which is a biochemistry and molecular

00:06:09.160 exercise physiology lab. So that's the condensed version of the academic path. Probably more important,

00:06:14.640 your question was college football, and then training professional athletes started at that

00:06:19.840 point as well. And then I started competing in weightlifting, which colloquially is Olympic

00:06:25.060 weightlifting, that version of it, and then combat sports a lot after that. So I've continued to work

00:06:29.380 with athletes the entire time. I'm still over the last 10 years, running my labs, running our research.

00:06:35.320 I've worked with professional athletes in just about every sport, with the exception of racing.

00:06:40.840 I have yet to get into Formula One. Cy Young winners, MVPs, All-Pros, the whole thing,

00:06:46.920 Olympic gold medalists, et cetera. So my research actually, and my interests really come back from

00:06:52.220 the exact same point. And so I'm going to return to the very beginning here, which was,

00:06:55.460 I was a decent athlete, but I actually feel like I was in the perfect spot because I wasn't so good

00:07:00.480 that these details didn't matter. I was going to be an All-Pro, I was going to go to the next level

00:07:05.700 no matter what. That wasn't the case. So when I did things better, I was more effective

00:07:09.560 with training, more effective with recovery. It mattered. I saw differences on the field,

00:07:13.120 right? It was the difference between me being a starter and being not a starter or whatever the

00:07:18.400 case is. I also was good enough to know where I got rewarded. So if you're not good enough,

00:07:23.720 then it's just like, it doesn't matter what you do, you're not going to play at the next level.

00:07:26.340 So I was in that perfect scenario. And so I was totally obsessed with making sure I gave myself

00:07:31.000 every advantage possible to have some success. I knew I was never going to be professional level

00:07:36.400 caliber or even division one. But I was like, the difference is, do you want to play college

00:07:41.480 football or not? That's going to be the difference. So if you can do these things, you might be able

00:07:45.140 to do it. If not, you're going to have no chance. And where I'm from, people don't really go to

00:07:49.420 college in general, and they certainly don't play college sports. There's no advanced degrees. And so

00:07:53.420 to me, I was like, wow, you got a chance to do something really special here and do something that

00:07:57.420 no one else you really know has done that often. So that's where that initial passion came from.

00:08:02.900 Additionally, the town I grew up with, my parents and everybody I knew, it is a very working class

00:08:08.460 place. And so losing was always fine. There's always better than you. But losing because you

00:08:13.680 didn't prepare was totally unacceptable. Most of the kids I grew up with, we worked on farms,

00:08:19.920 or we cleaned stalls, we did something before school. You know, my parents worked in construction,

00:08:24.440 like building. So that whole idea of like, you fend for yourself, and you get what you earn,

00:08:28.620 and all that sort of stuff was just something I grew up with. And so moving that into sports and

00:08:34.100 academia was like, if you want a chance, like this on you and nobody else. And so do the work

00:08:39.300 or don't do the work. So that's what all pushed me to get here. And then as I'll finish up, the

00:08:44.120 background is, then when I started moving past my athletic career, and I started finding athletes

00:08:49.340 who wanted to pursue these tremendous goals, like go to the Olympics, but in a sport like women's

00:08:55.700 wrestling, like no one's going to help them, they don't have funds. And so I just became very

00:08:59.900 interested in these people, because I'm like, man, I can help you a lot. No one else cares about

00:09:05.440 you. There's no money on the back end here. There's no fame, there's no social media at the

00:09:09.840 time. I just want to get help you here in this journey, because that's something that's going

00:09:14.020 to reach my soul of, let's give everything we can to do something really special that no one's

00:09:19.140 going to care about, besides you and I, and like your team and your family. And so that's what

00:09:23.420 drove it initially. And that's what really put me in this position. And that's what put me in a

00:09:27.460 position to continue to go and get my master's to get my PhD was you got to learn more. There's

00:09:32.360 more things going on here. You've got to find all the answers that you can. And if you're doing

00:09:36.780 anything less than that, what are you doing? You're just giving up. That's the background of how I got

00:09:41.100 here and what I do now. And you mentioned briefly, Olympic lifting. We've had Lane Norton on the

00:09:46.900 podcast several times. Lane obviously is a very successful power lifter. I think folks are kind of

00:09:52.380 familiar with power lifting, having the three lifts. And it's really about these three lifts

00:09:57.500 and what your total is in those three lifts. Can you contrast that a little bit with what Olympic

00:10:02.720 lifting is? And I think more importantly, what are the physiologic differences between those two?

00:10:09.220 And I'll preface the question for the listener by saying, again, even if you never plan to power

00:10:14.700 lift or Olympic lift, this is going to be germane to our discussion. There's actually a fairly

00:10:19.500 recently we published the most in-depth analysis of muscle composition of Olympic weight lifters.

00:10:24.420 So we can actually come back to that and we can talk more specifically about muscle composition,

00:10:28.120 but in general, as some background, if you think about power lifting, it's tricky because we're about

00:10:34.500 to run some loops on your brain here. So technically you have force production, which is in the case of

00:10:40.600 lifting, it is one rep max. So it's the most amount of weight you can lift one time period,

00:10:44.840 not repetitions on how many times you can do it, not how fast you can do it. Just what can you get up?

00:10:48.840 And the sport of power lifting, like what Lane does, it is three exercises, the deadlift,

00:10:54.300 bench, and the squat. And it's how much weight can you lift one time? You get a couple of tries

00:10:58.280 at it, but that's effective what it is. So it's really an expression of pure strength.

00:11:02.960 It's not really an expression of power at all because the speed component is very poor.

00:11:07.060 In fact, the deadlift can take as long as you want. It doesn't matter. Did you get it up or did

00:11:10.400 you not? Squat, et cetera. So we're already at the gates which confuse people because the name of the

00:11:15.520 sport is called power lifting, despite the fact that it is not a power exercise, nor is it determined

00:11:19.680 by power. When you move over to Olympic weightlifting, it's the same basic idea. There are now two lifts

00:11:25.360 instead of three, one lift being called the snatch and the other one's called the clean and jerk.

00:11:29.540 It's called the clean and jerk because it has two parts. You clean it to your chest and then you jerk

00:11:33.100 it over your head, but it's still considered one lift. The name of the game is still one rep max.

00:11:37.820 So whoever can lift the most amount one time is the winner. There's no repetition method to it.

00:11:43.400 The difference is though, this is now more expression of power because although it's all

00:11:49.080 about one rep max, it's difficult to lift something over your head as high as possible slowly. So

00:11:54.520 there's a speed component required to the movements to perform, whether it's the clean or the snatch.

00:11:59.320 And so it is an expression of tremendous strength, but there's this velocity component to it. So when you

00:12:03.900 multiply force by velocity, now you've got power. And so technically the weightlifters,

00:12:10.280 Olympic weightlifters are significantly more powerful than a powerlifter, despite the fact

00:12:15.100 the powerlifter is in a sport called powerlifting. So the confusion there is, and this gets worse

00:12:19.120 when we start roping in things like strongman. Strongman is fantastic because again, you see

00:12:23.720 strength and you think that must be the biggest expression of strength. Or in fact, it's not because

00:12:28.100 strongman is contested over multiple repetitions. So it is an expression of very, very high strength.

00:12:33.900 Repeated several times, very, very high strength, but it's not technically a true one rep max that

00:12:39.860 actually goes to the back of the powerlifters. So now you've already confused powerlifting,

00:12:42.980 weightlifting, and strongman. And none of those three things are actually explaining what they

00:12:47.340 do correctly. We can keep going on with multiple sports here, but this is the core of the problem.

00:12:52.300 The reason I think you're bringing this up is this also explains training adaptations. It's a perfect

00:12:57.660 way to outline, to understand what's happening. So if you train like a powerlifter,

00:13:01.240 that's probably represents the best way to get truly strong. If you train like a weightlifter,

00:13:06.520 it represents the best way to get powerful. If you train like a strongman, it represents a

00:13:10.880 fantastic way to get very, very strong and more, what we'll say life functional movements. So walking,

00:13:17.520 carrying, lifting objects, and doing it probably multiple times. So the only difference between all

00:13:24.240 those three, the last part I'll add to is with Olympic weightlifting, the amount of coordination

00:13:28.360 required, because you're going to take a weight from the ground, throw it over your head and catch it

00:13:31.800 over your head in a full squat. So when it comes to things like balance and proprioception and

00:13:36.780 eccentric catching, the advantage goes to weightlifters, you know, big time there, you're not going to see

00:13:41.420 that powerlifting is very controlled. It's a very specific foot position, hand position, there's no

00:13:46.680 movement, ideally. It's typically you're minimizing range of motion intentionally, because you want to

00:13:52.600 minimize work, working force times distance. And if the game of the game is who can create the most

00:13:57.060 force, you can minimize the distance, you're going to win. And that's why they take those funny

00:14:01.220 positions. That's why Lane has both of his feet, six miles apart. He calls it a deadlift, even though

00:14:06.500 it's a fake movement. Just kidding. Lane and I go back many, many years. So he would laugh at that

00:14:12.420 joke, I promise. So that's the basic foundation of the difference here. You have a very sports specific

00:14:18.500 application for powerlifting. Weightlifting is very sports specific, but it's a much greater range of

00:14:23.860 motion, has those other components. And strongman is kind of efficient. I didn't know you didn't ask

00:14:28.260 about strongman, but I threw it in there because it kind of rounds the loop out. I love that you

00:14:32.360 brought that in. Before I go on to my next question, let's put one more little bow on that. We've talked

00:14:36.760 a lot about who's the strongest, who's the most powerful, who has the most functional strength.

00:14:42.100 You want to throw in a little bit on hypertrophy within the trio? Yeah, great. So you can actually add a

00:14:47.100 couple of more scenarios here. Hypertrophy would be more of your bodybuilding, which Lane has also done.

00:14:52.580 I think you just had Holly on, right? So Holly can smash with physique, whether you want to call it

00:14:57.120 bodybuilding or general physique or any stuff. It's simply improving generally leanness and total

00:15:03.220 muscle mass. And then there's a component of symmetry and shape, things like that, that don't

00:15:06.920 really matter for this conversation. So if you add that on top of it now, you're talking about who

00:15:11.620 can optimize muscle size as well as leanness, which is really, really important with no consideration

00:15:17.000 for function. It doesn't matter if you're strong or fast or athletic or any of those things.

00:15:23.300 And so there, in fact, this is, it's so interesting here that you started the conversation like this,

00:15:27.460 because this is day one of my strength and conditioning courses, the academic semester.

00:15:32.580 I spend the first week actually just on going over these different categories of sport,

00:15:36.960 because it does exactly like what you're setting up here is it outlines exactly how to train. And

00:15:41.400 the last two pieces, just to throw this in there would be actually, if you think about the

00:15:46.860 competitive circuit training sports, the CrossFit, for example, totally, no offense. I'm just

00:15:52.520 meaning it as a sense of they are very strong. They have a lot of muscle, but they're not nearly as

00:15:56.820 strong as power lifters as a general statement. They're not nearly as strong as world's strongest

00:16:00.600 men, but they do a lot more repetitions. And so a world's strongest man is going to win

00:16:05.520 an event doing something like five to 15 repetitions, like something, you know, kind of

00:16:12.160 depending. In CrossFit, you might have to do 90 reps in a given workout, like way more. And so it's

00:16:17.160 way higher up that scale of number of repetitions. They do some, of course, that are one repetition,

00:16:22.300 but you get the point. It's just like a very crude explanation of what's happening. A lot of

00:16:27.540 function, a lot of different movements, and a lot of workouts repeated in the same day. And so it's a

00:16:32.200 very different test of recovery over three or four days of just brutal onslaught and asked to do

00:16:38.060 things in a lot of different areas and a lot of different energy systems and movement patterns and

00:16:41.340 things like that. So it's a really interesting test of total physical fitness. And the last one that I

00:16:46.240 like to throw in there is basically track and field. And now you have the truest expression of

00:16:50.000 velocity. These are the people who are going to be the best at getting you truly fast. And so if you

00:16:54.880 think about this now, what do you need to have as a functional human being for lifespan, longevity,

00:16:59.300 mobility, or sport? And if you want to think about this in a spectrum, how do I get absolutely

00:17:04.480 fastest? How do I get the most powerful? How do I get strong? How do I add muscle size slash lose

00:17:11.900 body fat? How do I improve my muscular endurance? And now how do I improve my cardiovascular and

00:17:17.400 metabolic endurance? This is now occupied in all of those sports. And so we can just look at them as

00:17:22.320 a model for training and saying the best in the world at getting stronger have been doing this.

00:17:26.420 The best in the world at getting faster, peak speed, the best in the world at getting able

00:17:31.680 to recover multiple days in a row. So we have different models of that. So that is a nice

00:17:35.940 foundation for all training, really. I love it. And there's a matrix brewing right now in my head

00:17:41.420 as you go through that. So we're going to come and kind of start to fill in some of this matrix as we go.

00:17:47.300 Let's simultaneously go back to the fundamentals, but do so without any remorse for how rigorous we need to

00:17:55.060 be. That's the greatest setup ever. Okay. So let's talk about muscles. What is a muscle?

00:18:03.760 What is the functional unit? How does it generate force? What are the metabolic demands? What makes

00:18:11.520 these cells that are so ubiquitous in our body different from, say, the cells in our liver,

00:18:18.540 the cells in our gut, the cells in our brain? What are these cells that we almost take for granted

00:18:22.900 sometimes? All right. Now you're asking me to do like a two semester course in 20 minutes or so.

00:18:29.560 Look, I did ask you to do a week in seven minutes. So by that logic, we could be here a while, but

00:18:35.420 yeah, let's see what we can do. All right. Hopefully you're ready for part two, three,

00:18:39.080 four, and five of this podcast. I'll give you what I can give you and then we'll come back. Let's think

00:18:43.440 about it this way. Number one, I like to play a little trick. You ever asked kind of like that

00:18:48.180 jeopardy question of what's the biggest organ in your body? And people generally are going to say

00:18:52.820 skin. Yeah, exactly. That's what I would have said, actually. Well, us again, exercise scientists.

00:18:58.140 And if I didn't give you enough of a bias earlier about being exercise scientists, I'm also a muscle

00:19:02.340 physiologist. So I'm going to give all the credit in the world, the muscle and none of it to anything

00:19:07.400 else. So basically the brain, the heart, the liver, the lungs, but they're just there to support the

00:19:13.640 muscles. A hundred percent. And if you start talking my worst enemy, the nervous system,

00:19:18.300 I'm probably going to hit and record and go home. Those neuroscientists just take credit for

00:19:23.280 everything. It's garbage, hot garbage, right? Give it all the muscle. So you've heard my biases. If

00:19:28.200 you want to stop listening now, you can, if not understand that as we're going here. And so in

00:19:32.280 general, if you think about it this way, again, muscle is going to be the largest organ in your body.

00:19:37.580 And you've talked about this a number of times on your show, but it's doing everything from

00:19:41.280 supporting function. And so locomotion getting you throughout the world to being your biggest

00:19:46.180 reserve for amino acids, which you need for building any cell, any functional cell in your body,

00:19:52.460 your brain, your liver, the immune system, all that has to come from somewhere to regulating glucose

00:19:58.120 being your biggest dump and reserve for regulating metabolism, controlling function. I could go on and on

00:20:04.480 and on about the physiological, the practical, uh, general health benefits of skeletal muscle.

00:20:12.460 And don't be bashful. This is a good time to say those things and to expand on them because

00:20:17.060 I've said everything you've said, but I think there's more to it. And I think one of the things

00:20:20.800 you've said, I don't think probably is as appreciated, which is the storage depot for amino acids,

00:20:26.700 because we don't really think of it that way. You know, and Lane did a great job talking about this

00:20:30.900 in the podcast, which is we're constantly breaking down and constantly adding new. So there's this

00:20:37.120 pool of turning over amino acids and it's very difficult to study them from a flux perspective,

00:20:43.760 but clearly some of those things getting spun off, you know, if you're working out, it's at least a

00:20:48.980 plausible scenario that amino acids are being, meaning proteins are being broken down, amino acids being

00:20:53.400 released. They may not be resynthesized right back into that same piece of skeletal muscle. They may be

00:20:58.280 used for another application. It's not even a maze. It's a pretty much guarantee that that's going

00:21:03.340 to happen. If you kind of think about it this way, I'll give a quick energetic analogy here.

00:21:09.460 I have like a cheesy video I did 10 years ago where I sat in my backyard and shot this and put it on

00:21:14.600 YouTube. We'll link to it, send it to us and we'll link to it in the show notes. Yeah. Okay. We'll find

00:21:19.020 out somewhere buried in eight year ago, YouTube land or something. So if you think about the very basics

00:21:24.920 of energy, if you were going to be out camping, you're an outdoorsman, right? Absolutely. Yeah.

00:21:30.080 Okay. Great. If you're out hunting, which I'm actually even a couple of days from my hunting trip.

00:21:34.280 So this is front of mind is why this analogy comes up. You know, you may need to create a fire. You

00:21:39.380 have a handful of options. And the very first one being if you had a match, right? A match is very

00:21:44.100 easy to light. And if anyone lights a match on fire, it's going to give you instantaneous energy,

00:21:49.860 the fire, and it's going to last some amount of seconds before it burns out. I don't know what those

00:21:54.080 seconds are. Five seconds, 10, 12, doesn't matter. Some short amount of seconds. Worst case scenario,

00:21:59.540 you need energy. Great. The downside is you have limited supply of them. They're kind of finicky

00:22:04.520 and you better hope they don't get wet and they're just not reliable. At best case, if none of that

00:22:09.660 happens, you're still going to get some amount of seconds. If you need the energy right now,

00:22:13.380 though, that's where you start. In terms of your tissue, that's going to be ATP. That's going to be

00:22:17.880 your phosphocreatine energy system. So the stoichiometry is one-to-one there. You break down one

00:22:22.000 phosphocreatine. You're getting one mole of ATP out of that. That's great. That's stored

00:22:27.460 internally in your muscle. So that's already right there. In fact, it's generally loaded right up on

00:22:31.800 the myosin head or close to it. And so it can contract tissue and we can come back to what all

00:22:37.100 that stuff means. We'll talk about actin myosin in a minute because I want people to actually know

00:22:40.820 what this physically looks like, but let's go back to the energetics. Great. So that's your little

00:22:45.440 energy boost system. Now, if you had a little bit more forward thinking, you would say, okay,

00:22:49.460 let me use that match to then actually just light a newspaper. If you had a newspaper or something

00:22:53.860 like that, and if you're in the woods, papers, same thing. You get fairly quick to light,

00:22:57.800 not as fast as a match. And it would give you some few minutes of energy. It doesn't matter what

00:23:02.560 these numbers are. It's just conceptual stuff here. And that's great. That's going to be

00:23:06.480 carbohydrate. So carbohydrate is stored both in the cell as well as outside the cell in three major

00:23:11.080 areas. But in the cell, it's going to give you a lot more energy. That is the most direct

00:23:14.700 fast stoichiometry is a little bit better, but not much actually. And so you're going to get a couple

00:23:19.360 of moles of ATP per molecule of carbohydrate. It's better, but it's like, you're sort of splitting

00:23:24.740 hairs here a little bit. If that gets low, you can now pull glucose out of the blood. And for a

00:23:30.720 little bit of terminology here, glycogen in the tissue is what it's called. Glycogen in the liver

00:23:36.620 is what it's called. We put that in the blood. That's called glucose, blood sugar, roughly talking

00:23:41.880 the same things here. So we can pull that out of the blood. And then we can actually, if that gets low,

00:23:46.620 we can pull that out of the liver. So that's the basic like energy pathway in the liver then

00:23:50.880 functions as kind of your backup storage system for glucose to make sure that you can regulate

00:23:55.340 blood glucose while you're changing concentrations of glycogen in tissue. That's really what it's

00:24:01.060 doing because you don't want, obviously, as you've talked about a million times, a bunch of

00:24:04.840 instability in blood glucose. That's a bad thing. It's one of the four things that your body will

00:24:08.900 regulate almost over almost anything else in addition to pH and blood pressure, et cetera. And

00:24:14.160 electrolyte concentrations, like they don't like to mess with those things at all. So everything else

00:24:18.680 will move around those things to keep those stable. All right. So if we're in the tissue now and we've

00:24:23.520 got past our newspaper, the next thing, it would be a giant piece of wood. So if you had firewood or

00:24:29.120 something like that, lighting firewood in the wild is very difficult to do. It doesn't happen in

00:24:34.260 seconds. You need to kind of know what you're doing, but it's going to give you exponentially more

00:24:38.300 fire length. I mean, you could put a log on a fire and that could literally be on going the next

00:24:43.400 morning when you wake up and give you hours. Think about that as fat. Now, I like this whole

00:24:47.960 analogy is if you know a little bit about the chemistry of fat versus carbohydrate, they're

00:24:53.180 both big, long chains of carbon. Just like a paper is actually made of wood is sort of just a separate

00:24:59.420 piece of the same thing. So you get a small six carbon chain from glucose. You can get any number

00:25:06.560 of lengths of chains of fat, 18 carbon fatty acid chain. You can put three of those on a backbone of

00:25:11.840 glycerol and you've gotten yourself 50 carbon molecules per triglyceride or something like

00:25:17.220 that. The stoic geometry gets better here. You're going to get something like three or 400

00:25:21.820 ATP per molecule of fat. And that's where things get actually better. Okay. The fat is actually

00:25:28.280 coming mostly though from outside of the muscle. So energy from fat mobilization comes throughout the

00:25:32.620 body somewhat evenly. Glucose comes mostly from the intra muscle itself. And then a little bit from

00:25:38.600 the backup supplies. If it gets low, phosphocreatine comes directly from the muscle. All that energetic

00:25:43.200 background to say, when you start moving and you start trying to create exercise, where's the last

00:25:48.580 piece we forgot here? Oh, that's protein. So protein actually in this analogy would be functioning more

00:25:54.540 like a piece of metal. So if you had metal in the woods and you needed a fire and you had absolutely

00:25:59.820 nothing else, you can in theory melt metal with a fire. You're going to get some, but it is a very,

00:26:07.520 very low end proposition. If you absolutely have to do it, you can do it to survive. But if that's

00:26:13.500 your fueling strategy, you're in a big, big problem because you're going to run out of metal very

00:26:17.260 quickly in the woods. You're out of it. It's also the only thing you have to create shelter and

00:26:22.360 stability and to fend for food and everything else. And so it is a plausible way to provide energy.

00:26:29.020 It's just a terrible one. It's mostly there for you to reconstruct new tools. And so if you're in the

00:26:34.900 woods and you have metal and you need to make a knife, you can fashion that. Okay. Now we need

00:26:38.660 to melt that thing down and make a roof. We can fashion that. Now we need to melt that back down

00:26:41.860 and make a shovel. It's meant to be kind of broken back down, recreated in the same and different

00:26:46.500 forms of the same basic item. And so that's really what we're looking at. The ability to play back and

00:26:52.240 forth with carbohydrate and fat as different fuel system. That's really, we don't have time to get to

00:26:56.300 that today. It's not really the best thing, but the ability and the need and the point of protein in

00:27:02.940 tissue, it is not fuel. Although it can be for what I explained, it's really that is taking it

00:27:08.440 and saying, we need it mostly for this task right now. We need it mostly for skeletal muscle. We need

00:27:14.120 it mostly for immune system. We need it mostly for these other functions. And so one of the ways to

00:27:19.480 quickly lose muscle is to put yourself in a compromised position because it's going to say,

00:27:24.480 if we're choosing between keeping that 24 inch bicep or clearing up something we need immunologically,

00:27:30.480 it's going to go towards that. This is also why we see protein redistribution across muscle.

00:27:35.380 Like say you spend a bunch of times on your bicep and your biceps get really, really big and then you

00:27:40.400 don't train your calf. And let's just say your protein intake is insufficient. You will start

00:27:44.960 redistributing proteins from the calf up to the bicep to actually enable that growth. And so you're

00:27:49.380 thinking you're getting bigger, but you're really just taking it from other places if protein intake

00:27:54.100 itself is not sufficient. And so it really is a cornerstone. And if you look at the research,

00:28:00.060 like you're going to see this like very clearly as something, if you ever wonder why some of these

00:28:04.260 people are just like so diligent about protein intake and why this has become such a big deal is

00:28:09.120 it's the raw material you really can't get anywhere else. And you can get carbohydrates and fat and you

00:28:14.480 can go through that whole thing in a lot of ways. You can't fake protein though. It's just very

00:28:18.560 challenging to do so. And the last little piece I'll say there is why this is so important to me

00:28:23.500 is you can't fake muscle most specifically without the protein. And when we start losing muscle,

00:28:29.940 now we enter a whole cascade of problems from physical performance. Your interest is more of

00:28:36.620 like aging and longevity, that whole cascade, it becomes a problem. And then we can certainly talk

00:28:41.280 about the specific changes in muscle and past some of the details you've actually covered before.

00:28:45.840 Yeah. Those are things like, it just becomes a really big deal. So it just doesn't make any sense

00:28:49.640 to skimp on that one as a place to go. Yeah. It's worth repeating. When you look at people

00:28:56.500 across their lifetimes and you evaluate for muscle mass and you divide people up and categorize them by

00:29:03.800 the amount of muscle mass they have. And we should talk about this because of course, my interpretation

00:29:08.700 of the data is that once you normalize for strength, strength wins, but it's sort of easier to measure

00:29:15.380 muscle mass. You know, all you need to do is put somebody in a DEXA and you sort of can figure out

00:29:19.180 their ALMI. And so we tend to look at survival curves based on ALMI, which for the listener just

00:29:25.440 means the amount of lean muscle you have in your arms and legs normalized to your height,

00:29:30.420 appendicular lean mass index. There's no ambiguity about the fact that more muscle means a longer

00:29:35.720 life. It's as clear as high VO2 max means a longer life. So let's now go back and make sure people

00:29:41.780 understand the structure of a muscle because I want to talk about different fiber types as well,

00:29:46.800 just to round out some of the physiology. So in an effort to understand the difference

00:29:51.400 between fast twitch and a slow twitch muscle fiber, which has a metabolic difference, I'm curious as

00:29:58.000 to what the structural difference is and maybe just kind of explaining how myofibrils work and things like

00:30:02.460 that. Let me go back just a little bit to understand whole human function movement. I won't go as deep

00:30:08.240 into this one though. If you just think about how you actually create movement, it really has three core

00:30:12.880 functions. So number one, you have to have some sort of direction or signal, and this is going to be

00:30:17.040 coming from your nervous system. And so whether this is central peripheral, whether this is autonomic,

00:30:21.720 whether this is a controlled somatic action response, it doesn't really matter for this

00:30:25.480 conversation. The nerve has to tell it what to do. So nerves, you get that one. That's it. Don't take

00:30:30.520 anything else in the nervous system. You get that control. Now that nerve then has to go into a muscle

00:30:35.940 fiber and tell that muscle fiber to contract. Okay. The muscle fiber then is part two. So the cell

00:30:41.020 actually has to contract itself, but that actually doesn't cause movement. Muscles are not attached to

00:30:45.840 bone. That's not how it works. So muscle fibers are surrounded by connected tissue. All those

00:30:50.580 connected tissue are bundled together in like a package. So if you imagine buying a bunch of strips

00:30:55.980 of bacon from the butcher and they would wrap that up and kind of saran wrap together, that's actually

00:31:01.300 kind of what a muscle looks like. So you've got that saran wrap connecting it. So if you pulled on one

00:31:05.200 piece of bacon, you'd notice the whole package moves. That's sort of the point. You're transferring

00:31:10.420 force from muscle through connective tissue. That connective tissue comes together into a tendon

00:31:15.680 and that tendon then attaches to bone. And so the third part for human movement is actually

00:31:20.700 connective tissue. And so you have to have a signal. You have to have a muscle contract that has to make

00:31:25.080 connective tissue pull on a bone. That actually is what generates human movement. Well, if you look at

00:31:29.720 the front end, we'll leave the neuroscience to other people. You look at the connective tissue

00:31:33.580 and it's very difficult to understand what's happening there for a number of reasons, but

00:31:39.520 mostly it's not plastic. When we look at muscle, it's tremendously plastic. And what I mean by that

00:31:44.200 is it adapts. It changes very quickly and rapidly in response to a lot of things. Connected tissues

00:31:49.320 doesn't have a blood flow supply, doesn't have an energetic demand. It's kind of just there.

00:31:54.820 There's more to that story, but we'll just kind of leave it like that. The core of the issue of

00:31:59.560 adaptations, whether they are pro or negative is going to be in skeletal muscle. And so here's

00:32:05.900 what that actually looks like. A nerve will come down and actually attach and innervate

00:32:10.300 to a whole host of muscle fibers. And so you can imagine skeletal muscle fibers are some of the

00:32:15.860 largest cells in all of biology by diameter. They're tremendous in humans. In fact, what's

00:32:20.580 actually very interesting about humans that makes us special is our muscle fibers are what's called

00:32:25.700 multi-nucleated. And so you probably remember this term from like med school or something like

00:32:32.020 that. In fact, whenever I talk to biology people about this, that like their head is blown because

00:32:35.820 I forget how lost in exercise science I get. It's very uncommon in nature to see cells that have more

00:32:41.060 than one nucleus. And the nucleus is the core of the cell, if you will. It's what holds your DNA.

00:32:45.040 It tells you when to replicate proteins to grow, shrink, die, repair. So the whole control center.

00:32:50.780 So the fact that skeletal muscle has many of them per cell, in fact, it's not a few,

00:32:56.720 it's not two or three, it is thousands per cell. So skeletal muscle can be extraordinarily large.

00:33:01.940 I have a video of this somewhere. I can't remember. Actually, there might've been a picture in a men's

00:33:07.960 health thing we did. There's a video somewhere. We'll find that. And we'll also put that in the

00:33:11.920 show notes. Okay. I can actually pick up a single muscle fiber from a human with tweezers and you can see

00:33:17.320 it with your naked eye. So we could hold this. In fact, I could do it right now. If I had one,

00:33:20.620 I could hold it in front of the camera and you'd be able to see an actual whole muscle cell.

00:33:23.880 They're that large. And in fact, they can be very, very long. So they can be several inches in length.

00:33:28.360 Let's help folks understand what defines a cell because normally outside of the muscle,

00:33:32.640 we kind of define a cell by a cell membrane as a single nucleus. I mean, we kind of know what the

00:33:37.460 constitutive elements here. This is defined also by a cell membrane, but it's a sort of a longer

00:33:43.360 looking tube as opposed to a sphere. Good distinction there. I sort of, again,

00:33:46.980 get lost in exercise science. If you remember like back to high school biology and you think

00:33:50.900 of a cell as like a circle or an oval, it's like that. It's circular, but it's a tube. So it's a

00:33:55.280 very long tube. The way to think about it is like a ponytail. So if you think about a ponytail,

00:33:59.140 you think about it as one thing. It is a ponytail, but it's made up of a whole bunch of long tube

00:34:03.900 individual hairs and they all wrap together to make a ponytail. That's what a skeletal muscle cell

00:34:09.140 looks like, which is actually quite different than a cardiac cell. Those are more rectangular,

00:34:13.060 if you will, that they're shorter and wider. Skeletal muscle fibers are very long, very narrow,

00:34:17.520 but still circular. They still have a cell membrane. They have a bunch of nuclei. Most of the organelle

00:34:23.020 are the same as any other thing. The contractile units we can get to in a second, but yeah,

00:34:28.520 that's the basic setup of them. Give me the typical length of a muscle cell,

00:34:33.560 a skeletal muscle cell. You can't really give a typical because depending on what you'll see with

00:34:38.960 skeletal muscle is structure is function. So if you contrast this to cardiac tissue,

00:34:43.660 so cardiac tissue is actually quite interesting because it is what we call the ultimate slow

00:34:46.600 twitch fiber. And so all of cardiac tissue is slow twitch. And in fact, the slow twitch are even

00:34:50.900 more slow twitch than the skeletal. And there tend to be fairly uniform. So you could give specific

00:34:55.220 numbers and cross-sectional area, a diameter length on those. Skeletal muscle, if you look at your

00:35:00.080 sartorius, which is that kind of muscle that goes from that pointy part of the front of your hip down to

00:35:04.940 the inside middle of your knee. Theoretically, those fibers could run the whole length.

00:35:09.620 A single cell.

00:35:10.720 Correct.

00:35:11.420 Can run that whole length.

00:35:12.840 Yeah. Even if it runs half that length, that's extraordinarily long. You go back though,

00:35:17.700 and you go to like an ocular muscle, it's going to be minute. It's going to be extremely small

00:35:22.620 in length. If you go to muscles in your digitize, your fingers, they're going to be very, very,

00:35:27.060 very, very short. There is no like classic range. It could be from millimeters to literally

00:35:33.020 inches in length. So presumably the reason that these cells have multiple nuclei is basically to

00:35:40.500 decentralize the actions of cellular construction. So you've got DNA making RNA in the proximity of

00:35:49.640 that nucleus coming out onto the Golgi making protein. And if you had, for example, even a one

00:35:56.840 centimeter long cell, which is enormous, outrageous, you couldn't simply make all of that work with one

00:36:04.720 nucleus. So the question is, does that mean these nuclei act independently? Where's the central command

00:36:11.600 on this? It seems like a remarkable problem. Remarkable problem, remarkable advantage. It's

00:36:16.940 the same thing here. Hard to control, but amazingly adaptive. Exactly. This is exactly right. So if you want

00:36:23.220 to dive down the entire nucleation question, this gets very, very interesting because we've actually

00:36:28.160 shown in our lab that a lot of professional athletes have more nuclei per volume. And so this

00:36:34.540 is one of the things that I posit is maybe this is why they can adapt so well. It's why they can

00:36:38.780 handle the volume that they can handle is they just simply have more of these nuclei around.

00:36:44.520 And you believe that that is how much genetic and how much adaptation to training?

00:36:49.380 Boy, I would love to give you an answer there. There's going to be a component to both. We actually

00:36:52.900 know numerous lifestyle factors that influence these things, but the more recent data are showing

00:36:58.340 this. In general, we have thought that nuclei have a couple of things. So one, it's not just nuclei

00:37:04.700 count that matters, which is what we previously thought. The shape matters. There's like spheres,

00:37:10.520 there's ovals, there are all kinds. And it looks like the shape determines the function. The location

00:37:15.640 determines the function. And so it looks like there are subtypes of nuclei that surround, for example,

00:37:20.800 the mitochondria. And they're going to be very specific to mitochondria repair. And then there's

00:37:25.100 other types that are more specific, the periphery that'll do cell wall damage. And then there are some

00:37:30.580 actually that are regulating injury specifically. This is what it looks like right now. And so there

00:37:35.880 are subtypes, and this is very, very recent understanding. And this is probably why some

00:37:40.480 folks will respond to injury more than others is they just simply have more of this subtype.

00:37:46.720 Now, your question of nature versus nurture, what's challenging about that is

00:37:50.180 the measurement fidelity here is difficult. And the tech is moving quickly, but it's sort of like

00:37:56.720 every couple of years when the microscopes get better, we sort of realized that all the three

00:38:00.440 previous years are now invalidated. And so there's just a lot of movement back and forth. And in fact,

00:38:06.320 if you look at this related to cell growth, in other words, hypertrophy, there seems to be tremendous

00:38:12.240 confusion about the role of these things in growth or not. So there used to be a thing that we referred

00:38:17.380 to as a myonuclear domain limitation. So in other words, a cell would only grow. So this would be your

00:38:22.460 fiber. It would only hypertrophy or grow in diameter to the extent at which the nuclei could

00:38:27.920 control it. And so in order to gain more growth, you actually have to get more satellite cells to come

00:38:32.740 in and add nuclei. And then when you detrain, that cell goes back down in diameter, but you preserve

00:38:38.820 the myonuclear number. And so then now retraining is easier than it was the first time.

00:38:44.660 I mean, this is unbelievable, but this is the old adage of muscle memory, quote unquote,

00:38:49.100 it's easier to regain muscle you once had than to put on muscle you never had. And I've never

00:38:54.900 heard a molecular explanation for that, but that's a very plausible mechanism.

00:39:00.060 Now it looks like that's not correct though.

00:39:01.560 You retain the nuclei. It looks like that's not correct. Interesting.

00:39:05.040 It's very back and forth is the way I'll say it. So something is there. The story I just outlined

00:39:11.320 to you, like it makes intuitive sense. I got really hot on it for a number of years. And then it was

00:39:16.300 like some more challenging data came out and it was like, well, we don't think so. I'm just going to

00:39:20.500 have to say like TBD. This is like every week another paper comes out and it's just like, okay,

00:39:25.880 now we're back on it. And now we're back off. And now we realize there's subtypes in myonuclear

00:39:29.960 and they're like, oh shit. Okay. It will lend itself obviously to a longitudinal type study.

00:39:35.200 I mean, in an ideal world, you would take relatively young, presumably pliable athletes

00:39:40.880 in their teens and study them over time under different training demands. Obviously the dream

00:39:47.160 case is doing it with identical twins. Which we've done. So I could just totally

00:39:51.540 interrupt you and go to that twin study if you want. Let's put a pin in it because I want to come

00:39:55.360 back to making sure people still understand how these things work. So we've now established that

00:39:59.800 muscle cells are kind of unlike any other cell in the body. How hungry are they for energy?

00:40:05.540 So for example, when we look at the liver, you know, I always think of the liver as a beautiful

00:40:08.720 organ, maybe not quite as cool as the muscle, but it has a special place in my heart because I've

00:40:13.700 always argued that the reason there is no extracorporeal support for the liver is we simply

00:40:18.460 can't replicate its complexity. For listeners, extracorporeal means outside of the body. So

00:40:23.220 dialysis is extracorporeal support for the kidney. A VAD or an ECMO is extracorporeal support for

00:40:29.600 the heart or heart and lungs combined. A ventilator, extracorporeal support for lungs. We can't do

00:40:35.300 that for a liver. If a patient tragically overdoses on Tylenol in an attempt to take their life and they

00:40:42.500 reach a point of irreversibly damaging the liver, you can't put them on liver support until they get

00:40:49.400 a transplant. That patient will be dead in about two days if they don't get a transplant. And I think

00:40:55.480 it comes down to a lot of the stuff you already talked about. Glucose homeostasis, one of the most

00:41:00.360 important bits of homeostasis in the body, is controlled with a level of precision I can't

00:41:07.140 fathom. I can sit and talk about the liver with the same level of excitement that you talk about

00:41:11.200 the muscles. And yet here's what's interesting. The liver is not a metabolically greedy organ.

00:41:16.260 It really doesn't on its own consume much energy. The brain, by contrast, a very complex organ,

00:41:25.100 an incredibly metabolically greedy organ, which is probably why we need the liver to support the

00:41:32.380 brain. Without the liver being so good at maintaining glucose homeostasis, our brain would

00:41:37.180 have either needed an adaptation strategy away from glucose where we wouldn't have brains as large as we

00:41:42.600 do. Where does the muscle fit into this hierarchy? Where is the muscle a high maintenance organ?

00:41:48.440 What's cool about the liver, it's kind of like a professional fighter where you can beat it up

00:41:52.520 a lot. That's right. You can't do much to the kidneys. They just don't have sustainability. I have

00:41:58.180 a secondary love for the liver because it's the closest thing in the body to skeletal muscle

00:42:01.680 in terms of the fact that it is listening and it will respond and it can change.

00:42:06.480 And as you said, very adaptive. Super adaptive.

00:42:08.580 You'll appreciate this if you didn't already know it. When I was in my residency, we would do

00:42:13.140 quite a number of live donor liver transplants. So this would be an operation where an individual

00:42:19.320 would donate a third to a half of their liver to another individual where there was a really good

00:42:24.420 HLA match. Well, here's what was really interesting. The speed with which that portion of their liver

00:42:31.380 would regenerate was so staggering that if you didn't anticipate it with inhumane doses of

00:42:39.800 intravenous phosphorus, they would have an enormous metabolic crisis. Oh yeah, totally. That makes sense.

00:42:46.860 There was no amount of food you could give this person to allow them to have enough phosphate backbone

00:42:52.940 for the DNA and RNA and protein synthesis that was going to be necessary to reproduce their liver.

00:43:00.320 So you just had to basically be giving them IV, FOS nonstop.

00:43:04.660 It sounds like what we have to do to fibers when we're doing our single fiber experiments. Like you

00:43:08.040 have to bathe them. You just have to have a permanent path of phosphorus. They won't go anymore.

00:43:12.280 That's right. And they could regenerate a third of their liver in two weeks. It's simply staggering.

00:43:16.920 And now, of course, the caveat for the person listening is this only works when the architecture

00:43:22.100 of the liver is preserved. So once you cross into the path of cirrhosis and inflammation,

00:43:28.580 it's over. So unfortunately, that person whose liver has been so beat up, for example, status post

00:43:35.060 NAFLD, NASH, or alcoholic liver disease, you get to a point where it no longer has that capacity to

00:43:41.300 regenerate. You know, the kind of the nice part about the story is though, if you fix it before that,

00:43:46.100 you have a good chance. Absolutely. So you can mess up for a long time. But if you do take that

00:43:51.100 action before you hit that level, I shouldn't even say it this way, but you can almost get back to

00:43:55.040 scratch. You can get a lot of regeneration there and a lot of recovery. You're right. And the kidneys

00:44:00.060 being so sensitive to blood pressure, so sensitive to the damage of high glucose, the lungs being so

00:44:05.920 sensitive to smoking and things like that. I just think the liver is an unsung hero of the body.

00:44:11.580 It's the thing that keeps you like, it's the bonk. You know, those from endurance sports,

00:44:14.920 when the liver is finished, it doesn't matter how much mental strength you have. It's a wrap. You

00:44:20.240 are going down. If you get hit in the liver, if you watch any sports, you get hit in the liver

00:44:25.560 instantaneously, you're crippled. It doesn't matter. You could be mentally, you're there,

00:44:29.680 but your body will seize and shut you down. Isn't that what happened to Oscar De La Hoya

00:44:33.240 against Bernard Hopkins? Do you remember that fight? I don't remember that fight, but I've seen it

00:44:37.560 500 times. I work a lot with UFC fighters and a number of, I have actually headline fight this

00:44:43.300 weekend for one of my guys. So yeah, I've seen it in those sports a ton. I've seen a little toe,

00:44:49.020 just the tip of a toe, click the liver and world champions just get locked up and fall on the

00:44:53.260 ground. It does not like being aggravated like that, but it will handle a beating for the most

00:44:58.280 part. You can beat it up pretty good. And if you see like any blood chemistry stuff, and if you're

00:45:02.900 looking at ALT, AST stuff and you're like, ah, you're pretty, it'll come back pretty quick. If you

00:45:07.420 take the right steps, the kidney is the one you see when you're like, Oh, we're not coming back to this

00:45:11.760 one. All right. So going back to muscle, it's a tremendously responsive to everything you're

00:45:17.380 doing and it's listening. So your question of how energetically demanding it is, there's a couple

00:45:21.180 of things to say about this. People will talk a lot about, Hey, if you add more muscle mass,

00:45:25.420 that's going to elevate your basal metabolic rate. So you'll burn more calories just sitting there.

00:45:30.280 That is true, but it's not to a level that you actually think it's probably, I think the numbers

00:45:35.540 are something like 30 calories with how much increase in muscle mass per pound per pound. Okay.

00:45:40.480 I think that's like something like that. It's not actually level. And you can make the argument

00:45:44.500 all after three or four years, that is that extra five or 10 pounds. Okay, sure. But it's not like,

00:45:50.420 I feel like some people think it's going to go from their basal metabolic rate is going to go from

00:45:53.340 1500 calories a day to 2,500 because they put on five pounds of muscle. That's just way outside the

00:45:58.800 realm of what's going to happen. There are many reasons you probably want to put some muscle on,

00:46:02.560 but like adding the metabolic boost. And that's because the question is how energetically demanding are

00:46:07.460 they actually think about it the opposite. Skeletal muscle is pretty lazy. It wants to be as efficient

00:46:12.560 as possible because if you think about functionality of physiology, you want your brain running full

00:46:18.260 course as often as you possibly can. You want continual interception of what's happening in your

00:46:23.340 outside world, as well as introspection going on. It's also making decisions, et cetera. Skeletal muscle

00:46:28.580 is simply like a backup system. It's think of more about it was like, what do you need done boss?

00:46:33.100 You need something done to elevate your function or on it. If not, we're going to sit down and shut

00:46:38.160 up and wait to be sort of pulled a little bit. And so what that means is if you need energy now,

00:46:44.960 muscle will jump to action. It'll get you going. We see this from everything from neat. It's like,

00:46:49.540 if you have this energetic need to burn 200 calories, your foot will start tapping. You'll

00:46:55.160 start doing sort of all these things. That's skeletal muscle going.

00:46:57.580 Tell folks what neat is.

00:46:58.680 This is non-exercise energy. So it's energy you're burning. That's not physical activity

00:47:03.640 or exercise or the energy needed to survive, to breathe, to digest, to go through basic stuff.

00:47:09.560 So it is the other 10 or so percent of energy throughout the day that accounts for people

00:47:15.260 losing weight or not losing weight or gaining weight that fluxes pretty well, depending on your

00:47:21.800 metabolic health, depending on your total size, depending on your other stuff. So if you ever see those

00:47:26.820 people who are like, man, they just can't sit still. Those are like colloquially the people

00:47:30.960 that probably have a pretty high neat. So they're just burning energy kind of sitting here.

00:47:35.140 Other people are more stoic physically are going to have sort of a lower thing. This is also one of

00:47:39.640 the things that explains how people can maintain the same amount of physical training, like

00:47:44.500 exercise performance, as well as health at tremendously different levels of calorie intakes,

00:47:50.240 because we can adjust neat very quickly. And your body is, it's kind of like a last bit of polish,

00:47:55.240 last bit of paint. Like what do we need to do here?

00:47:57.820 There's a huge buffer in there where you can increase decreaseness.

00:48:00.800 Yeah. And depending on what you need to do. And so we can kind of change our metabolic set point,

00:48:04.640 if you will, to keep you at the same potty size, irrelevant of going up and down in calories.

00:48:09.080 And I'm sure you guys cover that a thousand times with Lane.

00:48:11.860 So let's talk about contraction. How does a contraction actually work? And why does a contraction

00:48:16.360 require ATP? What part of the contraction needs it?

00:48:19.480 If we go back, nerve is coming into skeletal muscle and it would, in some instances,

00:48:24.540 like the eye actually, we have what's called a motor unit. So we have a motor unit across all

00:48:28.640 these things. So motor unit is the nerve that's coming in as well as all of these single fibers

00:48:32.960 that that nerve is innervating. So what that means is in the eye, for example, you have motor units as

00:48:38.420 small as almost one-to-one, which means there's a single motor unit coming in and activating a single

00:48:43.940 muscle fiber. That gives you extraordinary control of dexterity. And so you have a lot of nerves

00:48:48.580 coming in to control a very small number of fibers. And that makes you have real high precision with

00:48:54.540 exactly where you're controlling. You contrast that to muscles like the glutes. You need a lot

00:49:00.620 of strength, force production of the glutes, but very low fidelity. You don't need accuracy of

00:49:04.680 hip extension in terms of...

00:49:06.680 There's basically just one thing. It's contract, not contract. I mean,

00:49:10.920 do it with as much force as possible.

00:49:12.920 Or not. And so you're going to have hundreds.

00:49:15.160 That's basically the only dimension you have to regulate is what is the force and speed of

00:49:18.740 contraction. Whereas with the eye, which is a great example, I'm glad you made that contrast,

00:49:23.480 our eyes have insane fidelity. And of course you have multiple interocular muscles.

00:49:29.320 A lot.

00:49:30.280 You have all of these muscles above, below on the side of the eyes and the amount of tuning that

00:49:36.120 has to happen to allow humans to be able to do what we do so well, which is very subtly pick

00:49:42.020 things up with our eyes.

00:49:43.100 If you contrast that to like your fingers, which we need to have, it's the second highest level of

00:49:46.780 fidelity we have to have. The eyes are still an order of magnitude higher in terms of fidelity

00:49:51.640 and accuracy of movement. It's not even close. I need to be very precise with my fingertips,

00:49:55.600 but my eyes are on a whole new level of precision of where we have to be. So if there's one-to-one

00:50:01.500 or one-to-two in the eyes, it could be thousands per motor unit in the glutes. On-off. On 50%,

00:50:08.320 20%, so you can stand erect. I'll have some sort of like 20% level of glute contraction

00:50:13.260 to full hip extension, vertical jump, explosion, squat, deadlift, whatever the case.

00:50:19.520 That's so fantastic. Okay. Continue. So nerve comes in.

00:50:23.200 So nerve comes in and does that. Now here's a couple of other layers. Without going too far in

00:50:27.840 a nerve, you're familiar, I'm sure, with said principle. So you have specific adaptation for

00:50:32.160 close to man. There's another principle in here called Henneman's size principle. So Eldon Henneman's

00:50:36.260 one of my favorite scientists. His principle basically says there's low threshold and high

00:50:40.280 threshold motor units. And what that means is there are some motor units that are very easy

00:50:44.460 to get turned on and some that you have to just aggravate the shit out of them to get them to turn

00:50:49.420 on. Let's make sure people understand what that means in terms of what's an action potential.

00:50:53.780 How does a nerve actually deliver its signal? We have this fun interplay between chemistry,

00:50:59.500 electricity, and chemistry. That's exactly how contraction works. So you have to go from an

00:51:03.500 electrical signal to a chemical signal back to electrical signal. So what happens is you've

00:51:07.220 got sodium and potassium and chloride are your main players. And chloride is a negative charge.

00:51:13.420 Potassium, of course, is positive and sodium is positive. The fun way to look up this and pay

00:51:17.980 attention to this, if you ever forget here is, Peter, you're probably more familiar with this than

00:51:21.280 I am, but look at patient assisted suicide with Dr. Morkian. You give a giant bolus of potassium to

00:51:26.840 somebody and they're just going to slowly stop, their heart's going to slowly stop protracting.

00:51:30.560 Why? Because the amount of potassium intracellular is going to become fairly equivalent to the amount

00:51:35.200 of extracellular potassium. And so the change in gradient electrically between the outside of the

00:51:40.140 cell, inside of the cell becomes neutral. And so no action potential occurs. And so what you need to

00:51:45.220 have happen is a change in electrical volt from outside of the cell to inside the cell. And typically

00:51:50.160 we're talking like negative 30 millivolts intracell. And there's, it's kind of a number. And once enough of

00:51:56.700 the sodium and potassium start moving in the correct directions, then the electricity changes

00:52:00.840 because our positives moved more negative, you get the idea. And boom, we hit this split of this

00:52:07.020 switch. And this is what we call all or none. And so skeletal muscle fibers can't contract at

00:52:12.660 different levels of force. What I mean is once you flick them on, they go on fully and that's the

00:52:18.720 only way they can contract. And so the analogy we use here in our undergraduate class is the light

00:52:24.460 switch. So once you hit that certain threshold of millivolt, the muscle fiber contracts as hard

00:52:30.240 as it possibly can. There is no way, there's no dimmer switch here. You can't go 80%, 85, 50.

00:52:35.700 It's a hundred percent. Once you get to that action potential, you actually see the millivolts just

00:52:40.840 rocket back up. And then there's this whole cascade of recovery. This is what your sodium potassium

00:52:46.220 pumps are doing to try to reset that gradient, put them back in the right direction. So you can have

00:52:50.360 another contraction. Again, this is actually what explains tetany. So if you contract that fiber

00:52:54.880 multiple times in a row before it gets back to reset, then it just feels like it's in an isometric

00:52:59.220 contraction or it's not actually how it works, but it's going to feel like that. What actually

00:53:03.820 totally off the top of it, but what actually happens is you have so many muscle fibers and

00:53:07.080 they're contracting and relaxing at such a fast rate to your muscle. It feels like the whole thing

00:53:11.060 is just locked up, but they're actually flicking on, flicking off.

00:53:13.400 And by the way, just so folks understand, explain to folks how despite an all or none

00:53:18.900 action potential and an all or none contraction of a single fiber, you can still get variable

00:53:26.880 degrees of strength at the level of the muscle. So this is the next part. This is why we had to

00:53:32.060 bring up Peneman's size principle. So within these motor units, you have sizes. Now, what's

00:53:39.300 interesting is most of the time in normal situations, all the muscle fibers in that motor

00:53:45.980 unit are of the same fiber type. Let's just say we had two motor units. One of those motor units is

00:53:52.080 slow twitch. And one of those motor units is going to be fast twitch fibers at interface. So if we had

00:53:57.740 five fibers in that motor unit or 500, it doesn't really sort of matter right now. We have a couple

00:54:03.520 of factors actually coming on, but they're going to be of all like type generally within that same

00:54:08.580 motor unit. So the only way that we relegate force production is this. We have to know that all

00:54:14.080 five of those muscle fibers, once they get turned on, are going to contract at full speed. So the

00:54:17.880 only way we actually change how much force we're creating a whole muscle is by altering how many

00:54:22.800 of these motor units get turned on. So the size principle tells us we're going to turn on the low

00:54:29.060 threshold units first. And so if you go to do what you just did, so you reached over and grab a glass

00:54:34.700 of water, it's probably best. We don't turn on our high threshold, high force production,

00:54:40.880 generally larger, not always, but generally larger motor units that have generally faster

00:54:45.160 fibers that are generally bigger. Number one, or two reasons why you don't want to do that. Number one

00:54:50.080 is we produce unnecessary force. So instead of slowly touching that glass of your lips, you'd smash

00:54:55.220 them off your face. You can't go down. So if that motor unit can produce five pounds of force

00:54:59.440 and you need two pounds of force, there is no way to go backwards. So you always start at the

00:55:04.300 smallest unit possible and turn on more motor units if more force production is required.

00:55:10.180 Secondarily, it just burns energy. So fast twitch muscle fibers are more metabolically demanding

00:55:15.300 than slow twitch muscle fibers. And so you're going to waste gas doing that. And this is exactly why

00:55:19.740 your car starts off in first gear, second, et cetera, et cetera. We lose efficiency as we go up,

00:55:25.960 but we gain performance. So let's use that example when you're talking, just going back really quickly

00:55:31.980 to the athlete. So how quickly is that response modulated when I want to deadlift something?

00:55:41.780 You can see this in real life. I have a video of a deadlift actually of a friend of mine

00:55:44.900 doing this where, so the initial step that's going to happen here, are you're going to activate

00:55:49.580 slow twitch, sorry, lower threshold motor units, which are going to be almost supposed to be

00:55:53.060 the only way that we really know to increase that is through force production demands. Like we're

00:55:59.520 going to come back to this when we get to fiber type stuff eventually for aging. And some of the

00:56:03.220 stuff that came out even this week, you may have not seen yet. The challenge with fast twitch muscle

00:56:07.480 fibers is they're only then based on this logic activated under high threshold demands, which are

00:56:15.080 high force demands. You can do anything to activate. And then the data will show this on aging.

00:56:20.000 You see virtually no reduction in slow twitch fibers with aging. You see no reduction in size. In fact,

00:56:27.360 there is some more than a few papers showing a hypertrophic effect of slow twitch fibers with

00:56:31.340 aging. There is no loss in velo. There's no loss in specific tension, which is like force per unit of

00:56:36.860 size. There's no loss of power. It just appears to be very easy with any level of activity to maintain

00:56:43.940 and preserve health of slow twitch fibers. But because fast twitch fibers require force production

00:56:49.120 and you generally don't get high force production and activities of daily living, then those fibers

00:56:53.780 go unutilized for long stretches of time. Eventually, they go away. And so what we see happen is this

00:57:01.440 really interesting thing called fiber type grouping, where the nerve will basically say, okay, that fiber is

00:57:06.500 being not used. That whole motor unit will decay and the fibers will be preserved. The other neighboring

00:57:13.460 motor units will actually grow new extensions, activate some of the previously gone motor units,

00:57:20.840 and then convert those fibers into whatever fiber type happens in that previous motor unit.

00:57:26.540 So in general, what we see happening here is slow twitch fibers start absorbing or slow twitch motor units

00:57:31.840 start absorbing fast twitch fibers and bringing them to their motor unit. And so we see these large

00:57:36.740 patches of single fiber types throughout the muscle. And so the last part of that puzzle is in a motor

00:57:44.040 unit, those fibers are connected by the same neuron and they're the same fiber type, but they're not

00:57:49.680 laying next to each other. You don't want them in the same spot. They're sort of dispersed throughout the

00:57:53.760 muscle. And so that gives you smoothness of contraction. And so one of the things that happens is if you start

00:57:59.640 punching like the entire right side of your bicep is one motor unit, the entire left side is when you contract

00:58:05.560 that motor unit alone, you get super spastic, out of control, and you get twitchy and unregulated movements.

00:58:11.340 And so when we see this fiber type grouping thing occur with aging, it's almost exclusively a problem of fast

00:58:17.540 twitch fibers, not loss of slow twitch fibers. And so that also explains lack of fidelity as well as potentially some

00:58:24.820 problems with fine unit movements.

00:58:28.220 What is the heterogeneity of fast and slow twitch mixtures within different areas? So presumably the eye is all slow

00:58:36.900 twitch. It doesn't particularly require much force.

00:58:40.020 It doesn't require much force, but it does require a lot of speed. So you need to be able to dart back and forth

00:58:43.960 quickly. So I actually don't know the...

00:58:45.700 Let's look at a big skeletal muscle like the lats or the glutes.

00:58:49.280 So we have two things you have to pay attention to here is we have a huge amount of person to person variations.

00:58:54.980 Within what bracket though? Give me a sense of presumably everybody has at least 20% of each.

00:59:00.460 I'm making that up, but is there...

00:59:01.860 Let me do the second part. We'll come back to that first part. So there's actually, as you're

00:59:05.420 alluding to a second ago, there's also tremendous difference between muscle to muscle. And so some

00:59:10.000 muscles, if we look at it, like if we compare my soleus to your soleus, you might be 90% slow twitch

00:59:15.340 in your soleus. I might be 70. And that would be a large variation in that muscle. If you look at animal

00:59:20.980 models, cell culture to any murine, like you're going to see a hundred percent slow twitch in a

00:59:25.280 soleus. And the reason is because we walk, the soleus has got to be a majority slow twitch muscle

00:59:31.600 fiber. You know, we just spend too much time ambulatory to risk any inefficiency in that

00:59:37.820 system. A hundred percent. If you look at the shank in general, you've got two primary muscles

00:59:42.000 of movement there. The soleus being the smaller one, they both attach at the bottom of your foot.

00:59:46.460 That's your panteras, right? So closer there. If you were to take your foot and your toe and like

00:59:52.100 point it towards your face and you were to flex your calf, that one that pops up, that has that

00:59:56.620 kind of U shape. If you have a nice calf anyways, that big one that pops up to the middle, that's

01:00:01.800 your gastroc. The one that kind of sits behind, it's underneath the very bottom where your calf

01:00:06.360 stuff kind of ends and it goes in that long piece. That's the soleus. And the gastroc is almost

01:00:11.320 the opposite. It is almost exclusively fast twitch, but not nearly as exclusive as your

01:00:16.160 soleus is. So the soleus is what we call postural or anti-gravity for the exact stuff you mentioned.

01:00:21.160 It needs to stay up and it needs to be on. In fact, you can actually have a soleus contracted

01:00:25.280 for hours and be totally, totally fine. And you won't even realize it for the most part.

01:00:29.740 It's actually good metabolically, but you would not realize it. If you contracted your gastroc for

01:00:34.180 more than a few seconds, we were probably going to feel the burn like pretty quickly.

01:00:38.380 So the variation in something like a soleus could be that. I think probably if you saw somebody

01:00:43.240 who's 30% fast twitch in the soleus, that's a very, very high number. I wouldn't be surprised

01:00:48.760 if I saw somebody 95 though. If you contrast that to a muscle like the VL, so the vastus lateralis,

01:00:54.820 that the quad, the outside quad muscle, as you know, but for the audience, now the variation gets

01:01:00.040 extraordinarily large. So in general, the VL is like what we typically say is 50-50 fast twitch low twitch.

01:01:07.980 And for the record, it gets far more complicated than fast twitch slow twitch, but we're just

01:01:12.340 kind of keeping it at that level for now. We have shown actually in our lab, a couple of things.

01:01:16.720 So one, we biopsied a whole bunch of people who are Olympians and world caliber, national caliber

01:01:22.140 in our lab, men and women. And some of those individuals are 80 plus percent, 85% fast twitch.

01:01:30.460 And by the way, just did you also do VM and why is there a difference between VL,

01:01:34.940 VM and intermediates just due to access? Generally access and safety, a lot more potential things to

01:01:41.940 hit in the medial, nothing off the outside. If I nick anything, we have problems.

01:01:47.540 You could be up to 80% fast twitch on your VL if you're, and by the way, is that true across all

01:01:54.740 sports? Like if you had the Tour de France champion, would you expect him to, even though he's the best

01:02:01.300 of the best and his VL is a monstrosity, would you expect him to have that high a fast twitch?

01:02:09.760 So in some of the folks we've biopsied in the modern space, they are as high as 90% slow twitch

01:02:15.220 in the VL. It's basically zero to zero. You can run the whole gamut of composition in the VL.

01:02:21.580 And we're back to the same question, which is if you had a time machine and you could go back and

01:02:26.200 biopsy them as five-year-olds, we really don't know what they looked like then.

01:02:29.900 Well, this is what our twin study did. Rather than biopsy them at five years old, we got lucky.

01:02:35.240 You biopsy them as adults as twins?

01:02:36.640 We got monosygous twins.

01:02:37.940 Who presumably had enough differences in what they were doing that you could see a signal if there was...

01:02:42.020 About 35 years difference of training.

01:02:44.500 And what did you see?

01:02:45.240 If we compare this now that I can go back and tell them, please. You've been in labs,

01:02:49.860 you'll appreciate this. One of our graduate students who'd been in our lab for probably three or more

01:02:53.780 years was sitting next to my colleague, Jimmy Bagley, and they're pulling muscle fibers.

01:02:59.020 Sort of like the things that come up when you're staring under a microscope,

01:03:02.080 pulling out individual muscle fibers with tweezers for hundreds of hours on time,

01:03:06.320 like your brain goes into weird spots. And so she was sort of just telling him,

01:03:10.020 oh yeah, like my dad's a twin or whatever. Oh, cool. Whatever. Oh yeah. Like monosygous.

01:03:15.400 Like, yeah. So monosygous means their DNA is exact. So not just brothers that got born at the same time.

01:03:20.600 So you have genetic replication. So we have that category lock. And then Jimmy was sort of like,

01:03:25.640 oh, cool. Did they exercise? And she's like, oh yeah. Well, like, I think I can't remember which one.

01:03:29.780 He's like, well, my dad doesn't exercise, but my uncle has been competing in Ironmans for 35 years.

01:03:35.800 And Jimmy was like, what? It's a dream experiment. Wait, wait. So let me get this straight.

01:03:40.540 You have identical twin parents, father. One of them has been 30 plus years of documented endurance exercise.

01:03:46.380 The other, what's he do? She's like, no, he's never exercised in high school. And we're like,

01:03:50.860 and you've been in my lab for three years. And this is the first we're hearing about this.

01:03:54.200 You're fired. You're not graduating. So we were able to pull them into the lab and bring them in.

01:03:58.000 And so he was one of these classic endurance nerds. Every workout had been documented for 30 years.

01:04:03.440 He's got 50 journals written down. So we knew the caloric expenditure. We knew the miles.

01:04:09.900 We just had everything, half marathons, marathons, all this.

01:04:13.280 And phenotypically, how different did they look?

01:04:15.240 Almost identical. Even with all the training, they still looked, I mean, I'm saying not in

01:04:19.720 the face, of course, but just muscularly, how did they appear phenotypically?

01:04:22.760 No, I know what you're saying. They were almost identical. The only exception was

01:04:26.140 the non-exercising twin was a little bit less lean. I think he had, I can't remember exactly,

01:04:32.440 but something like three or four more kilos of body fat, maybe less.

01:04:35.520 Isn't that kind of amazing too? Do you know what their muscle looked like though?

01:04:39.020 It really speaks to the hereditary nature. Well, yeah, yeah. So, so I want to come back to

01:04:43.840 that because that's what's important. But at the surface, think about that. You have these two

01:04:48.540 guys that are genetically identical, presumably both looked good. And one is by all intents and

01:04:54.480 purposes, a fanatic around exercise. The other is a couch potato, but on the outside, they look

01:04:59.860 relatively equivalent. Tells you a couple of things. One, body habitus is remarkably hereditary.

01:05:05.900 I mean, it is, I believe more hereditary than, it's certainly on par with height and eye color

01:05:12.320 in terms of how hereditary it is. The second is what you're about to tell us, I suspect,

01:05:17.440 which is that the outside is but a fraction of the story.

01:05:21.620 So here's what we did. I got super excited and I was basically like, I'm going to take every measure

01:05:26.460 possible. It's this DEXA scans. This is vertical jump, VO2 max, blood chemistry, muscle biopsies,

01:05:35.900 psychological evaluations with an IQ test. We just did everything we could possibly do.

01:05:41.480 The total amount of lean maths.

01:05:43.540 By the way, you'd created just a random IRB to do this? Like what?

01:05:47.040 Oh, yeah. I mean, like we took time to design the study, put an IRB through the whole sort of thing.

01:05:52.400 How long did it take just so people understand the pace at which science moves from the microscope

01:05:56.600 discussion until you've got these guys in your lab?

01:05:59.200 Maybe eight months.

01:06:00.240 Oh, wow. That's really fast. You already had the funding, I assume?

01:06:04.060 Yeah, I didn't care. I'm paying for this regardless, 100%. In fact, I literally did pay

01:06:09.780 for their plane flights out of my pocket. I didn't want to deal with the stuff. I was like,

01:06:13.360 just book the flights right now. We got to schedule the work, put it on my credit card. I don't care.

01:06:17.880 I'm not missing this chance.

01:06:20.540 So what did you see?

01:06:21.700 What's interesting was the body composition wise, the untrained person was, again,

01:06:25.780 five, six pounds more fat mass, something like that. Maybe three kilos was too high. I can't

01:06:31.120 remember. So I'm like, oh, that's interesting.

01:06:32.720 On DEXA, what was the difference in muscle mass?

01:06:34.840 Like 100 grams. I think the number was 71.

01:06:38.440 You're at the detection rate.

01:06:39.320 Way beyond.

01:06:40.080 So they're essentially identical.

01:06:41.580 They were almost identical and totally in muscle mass, right? Now, interesting,

01:06:46.560 the endurance guy did not lift at all. No strength training whatsoever. Strictly running cycling

01:06:51.720 swimming, like a very classic.

01:06:53.860 Can you imagine just the Godonkin experiment of triplets where you had a third guy here that

01:06:58.280 only lifted weights? Can you just imagine?

01:07:00.440 I can't. Like this was like an hour of her thesis defense.

01:07:03.440 This was that question right there.

01:07:06.420 Okay. All right.

01:07:07.860 We actually did another study in Stockholm, Sweden with lifelong skiers. I won't get too

01:07:13.060 derailed here, but these are people who are world champions, the 1940s and 50s in cross-country

01:07:17.040 skiing, Olympic gold medalists, and didn't stop competing. Now they're in the age of 85 plus

01:07:22.000 up to 92 years old and we're still competitive skiers and compare them to age match healthy

01:07:26.960 folks over here in America. So I've spent a little bit of time in this like aging athlete

01:07:31.480 thing.

01:07:31.880 I actually wrote a little bit about that cohort in my book.

01:07:34.440 Oh, really?

01:07:35.140 The skiers. Yeah.

01:07:36.120 Yeah. That's us.

01:07:36.820 It's insane what they're capable of doing.

01:07:38.160 I could tell you a lot more behind the scenes on that one.

01:07:40.400 I'd love to. Yeah. Let's come back to it.

01:07:42.640 Walking into the hospital across the street and just like jumping off the curb because there

01:07:47.020 was ice. And you're like, oh, you're in 90. And you just decided to jump that curb for fun.

01:07:52.000 Like when no one was watching you, because we could like see them from the window coming

01:07:54.960 in. I'm just like, just, so just like one guy finishing a VO2 max sitting on the chair,

01:07:59.600 taking like two breaths and goes, I didn't understand the test. Let me try it again.

01:08:02.440 I'm trying to get back on the mic. This is like 12 seconds after VO2 max and a whole bunch

01:08:07.940 of other stuff. Like that was incredible. So back to the twin studies, that was identical.

01:08:12.580 In general, you could categorize some things. So I'll kind of make this a little bit shorter.

01:08:15.840 If you looked at muscle quality, so this is echo intensity and an ultrasound. This is vertical

01:08:20.940 jump. This is leg extension strength. It was either identical or it favored the non-exercising

01:08:27.080 twin. Everything else that you would classically associate as an exercise adaptation favored the

01:08:32.580 exerciser. Blood lipid panel, blood pressure, body composition. Certainly VO2 max was significantly

01:08:39.720 higher. Resting heart rate, like all the classic textbook endurance exercises, A, B, and C,

01:08:45.540 it's stacked up exactly as you'd think. The neutral stuff, total muscle mass. That was basically on

01:08:53.420 point. And then a blood glucose was favored for the exerciser. Like all that stuff you would predict.

01:08:58.540 But just to make sure I understand the non-exerciser was stronger,

01:09:02.680 stronger, better jumper, higher quality muscle.

01:09:06.180 Go into the higher quality again to make sure I understand that beyond the metric driven stuff.

01:09:10.560 Is that a subjective assessment of muscle quality?

01:09:13.600 No, no, no, no, no. You can actually measure this via an ultrasound. And so this is like a measure of,

01:09:18.120 it's called echo intensity. It's a measure of, it's akin to measuring how much intramuscular fat

01:09:23.460 is inside the actual tissue. That's what echo intensity is kind of basically tell you.

01:09:27.920 So you're saying the exercising guy had more intramuscular lipid.

01:09:32.380 Right.

01:09:32.600 Just to play devil's advocate, isn't that an adaptation to his endurance training where he

01:09:39.000 wants to have more intramuscular lipid because he wants to have more logs near the fire? He's

01:09:43.420 burning those logs.

01:09:44.780 Totally. And you wouldn't have to dig hard to find support for that.

01:09:47.600 And I think that's different from the intramuscular lipid we see in the diabetic,

01:09:51.820 for example, or in the insulin resistant.

01:09:54.040 There's a level when you cross. When there's no exercise there, then there's a different reason

01:09:57.640 that that happens.

01:09:58.560 But still, what's interesting to me is that the strength metrics also favored the non-exerciser.

01:10:04.660 It was all favored to neutral. Either some of the metrics were similar or not statistically

01:10:10.340 different, but they hedged towards the non-exerciser. So you could say at best,

01:10:14.640 they were neutral to favoring the non-exerciser is I think the most fair way. But there was not a

01:10:20.540 metric there that favored the exerciser on that side of the house.

01:10:24.000 So what is your...

01:10:25.060 Biopsy related.

01:10:26.340 Yeah. Let's talk about the biopsy.

01:10:27.420 It gets very different. So I'll give you the quick version. There's a more interesting version.

01:10:31.660 The non-exerciser was almost identical to what you'd see in the literature and what we've done

01:10:36.200 a ton of times where you have something like you're fairly mixed in terms of phenotype. So

01:10:42.000 you've got some percentage of fast twitch, some percentage of slow twitch. But in fact,

01:10:45.500 he had about, if I remember correctly, something like 20% of his fibers are in what we call this

01:10:50.140 hybrid format. And so I sort of alluded to this earlier. There's fast twitch fibers and slow twitch

01:10:54.120 fibers, but the story goes much deeper. That's not really how the whole thing plays out.

01:10:58.360 So these hybrid fibers are a single individual cell. So one muscle fiber that co-expresses fast

01:11:03.900 and slow twitch. And in fact, it'll express that in different areas throughout the length

01:11:08.540 of the fiber. So it'll be exclusively fast twitch in one portion, fast and slow in another portion,

01:11:13.660 and exclusively slow twitch in another portion, et cetera.

01:11:15.680 Let's make sure people understand what the difference is between a fast and a slow twitch

01:11:19.040 fiber. I want to come right back to where we are, but I just want to make sure we haven't

01:11:22.560 lost that.

01:11:23.080 In general, there's a lot of ways to describe it, but the easiest way is to describe it by

01:11:26.900 the name. So fast twitch means that the twitch or the speed of contraction is higher. These fibers

01:11:32.900 can contract and squeeze together through the mechanisms. We haven't got to yet. We'll get

01:11:37.160 there. Myosinactin at a much faster rate. Having said that, the fast twitch fibers tend to be

01:11:42.460 larger, though not always, and certainly not in endurance training individuals and definitely not

01:11:46.980 with aging. They almost always are more glycolytically driven. And so they're going to have more of the

01:11:51.840 enzymes responsible for anaerobic glycolysis. They're going to have more glucose in the cell.

01:11:58.080 They're going to have less intramuscular triglycerides. They generally have more phosphocreatine.

01:12:02.960 Slow twitch fibers are fatigue resistant, which means these are the ones that contract kind of all day

01:12:08.920 long because they don't use as much glucose. So they do use quite a bit still.

01:12:12.820 They are much better at using fat as a fuel. They tend to have more and larger mitochondria.

01:12:18.480 The downside is they don't contract with as much velocity in general. So that's the functional.

01:12:23.400 That's why we call them twitch. And just to be clear, the force difference between them,

01:12:30.380 it doesn't matter. It's just velocity or is there a force difference as well?

01:12:33.880 So a couple of things. In large part, force production from muscle fibers is determined mostly

01:12:38.680 by size cross-sectional area. So getting the fiber bigger is the play to get it faster. Having said

01:12:44.240 that, power is markedly different. Because power is based on velocity as well.

01:12:48.380 You multiply the force by the velocity. So if you use this metric that we'll use in single fiber

01:12:52.860 experiments called specific tension, which is sort of like relative strength, you take the size portion

01:12:58.480 out of the equation. What you're going to see is a true slow twitch. So these are also called type

01:13:04.120 one fibers. If you compare those to a type 2A, so that's a fast twitch muscle fiber, you're going to

01:13:11.080 see something like 5 to 6X power between these two. So it's not a small...

01:13:15.620 When you normalize for size, when you normalize for cross-sectional diameter.

01:13:18.680 If you go to the 2X fibers, which is a special class of fast twitch fibers, now you're talking 20X,

01:13:25.940 that power.

01:13:26.280 And that is mostly explained by more metabolic apparatus. What's enabling the speed?

01:13:34.260 No.

01:13:34.920 Why does the 2X fiber go faster?

01:13:36.560 In fact, the way that we differentiate muscle fibers in a laboratory is we measure what's called

01:13:41.680 the myosin heavy chain to kind of actually come back to microanatomy here. So the way the muscle

01:13:47.280 fibers work is this is all in a 3D sequence. So you can imagine that cylinder. I'm going to explain

01:13:52.640 it to you in 2D to see you understand, but this is actually occurring in 3D. And so what happens is

01:13:57.400 you've got two of these microfilaments called actin and myosin. What happens is they're overlapped,

01:14:02.920 so they're not touching each other. And you've got myosin kind of laying in the middle and it's

01:14:07.020 this big, thick tube. And it's got these heads that flick off the top of it. Now these heads reach

01:14:13.380 up and they extend again in 3D, but if you just think about it in 2D, they reach up and grab on

01:14:17.780 what's called actin. The idea when you contract the muscle is the myosin will reach up and they're

01:14:23.560 going to reach out outward. So if you're watching this video, you're seeing my hands kind of reach

01:14:27.580 up and away from my body. Like I'm stretching my arms, like I'm doing a big T, if you will.

01:14:32.400 And my hands would then grab onto the actin. And then if I were to squeeze my hands and bring my

01:14:37.600 hands closer to my face, the myosin is actually then pulling the actin closer together. So what

01:14:42.400 actually happens in real life is those start stacking on top of each other. And that's why

01:14:46.440 when you squeeze your bicep, it actually glows larger vertically because those muscle fibers are

01:14:51.020 stacking on top of each other and that's actually elevating in size. And so what determines force

01:14:57.560 production versus velocity is what we call cross bridges. So the amount of time that these myosin

01:15:03.140 heads grab onto actin, that little place of connection is called a cross bridge. The more

01:15:08.500 those cross bridges you have, the more effectively you can pull the actin closer to each other. The

01:15:14.260 more effectively you do that, the faster the contraction, the more forceful the contraction is

01:15:18.120 going to be. So primary thing explaining force production is the amount of cross bridges.

01:15:24.460 So the thicker your myosin, the more likely you are to grab actin, the faster, the stronger the

01:15:31.220 hold, if you will. So the better connection your hand has to that thing it's grabbing onto, rather

01:15:35.320 than you can imagine like a couple of fingertips on it and trying to pull something closer to you

01:15:39.600 versus having your whole hand wrapped around it, a strap on it, chalk on it. You're going to be able

01:15:44.220 rip that thing down quickly. Now there are six actin that surround in a circle each myosin in human

01:15:52.380 skeletal muscle. So again, a picture of that 3D structure. So you can imagine if I'm standing up

01:15:57.400 in a room and I'm myosin and six people are forming a circle around me, like they're going to

01:16:02.360 jump me or celebrate me or whatever. That's what it looks like. And my arms can sort of reach out.

01:16:06.840 And no matter where my arms are, there's going to be somebody that I can grab.

01:16:10.020 And you only have two arms still in this? You only have two myosin filaments?

01:16:14.960 You have a ton. So you have one myosin filament.

01:16:17.500 I'm sorry, you only have two heads or how many heads do you have?

01:16:20.560 Bajillions.

01:16:21.080 Okay. So you have billions of heads to grab onto six potential targets. So you're always going to

01:16:25.340 grab a target.

01:16:26.220 You're going to grab one, right? Now you can't increase the amount of those actin that are around

01:16:30.340 you, but we do see that in other animals. So this is one of the reasons that explains why like

01:16:35.920 fruit flies, spiders, and things like that can contract with so much more force relative to

01:16:40.960 humans is they might have eight or 10 or 12 or 20 myosin or actin per myosin.

01:16:46.120 And ants, which we always think of as like for their size being insanely strong,

01:16:50.260 they'll do that. So evolution's tool to make things stronger is give more actin because you

01:16:57.140 already have an infinite number of myosin heads. The more things I can give you to grab onto,

01:17:00.800 the stronger you are.

01:17:01.800 The stronger you're going to be.

01:17:02.600 You realize there's somebody out there using CRISPR right now, trying to figure out

01:17:06.880 how to double the number of these things in humans, right?

01:17:11.120 So I'm not going to say this officially. All I'm going to say is, well, officially the world knows

01:17:16.780 about the bear muscle studies that we've worked on. So there have been bear tissue come through

01:17:21.960 and under my microscope, put it that way. Bear tissue is actually quite unique. So they actually

01:17:26.460 have a, so humans have that 2A and they have that 2X.

01:17:30.280 Which is formerly 2B, right?

01:17:32.780 Incorrectly identified as 2B. That's correct. Most other animals do actually have, in fact,

01:17:37.800 2B. And the 2B is even faster than the 2X. And bears have a lot of them. So this is one of the

01:17:43.760 other reasons why they simply have a fiber type that is much faster than any of the fastest ones

01:17:49.600 we have. Cheetahs, other cats like that, have like 20 to 60% of these 2B fibers. It's extraordinarily

01:17:55.460 high amounts, which allows them to go super fast. And in those, do they have more actin targets?

01:18:00.680 I think cats are pretty close to six to one. We could fact check that one, but I'm pretty sure

01:18:05.020 that part of it tends to be fairly similar around mammals. It's when you get to the insects and

01:18:09.300 things like that. I think when that number jumps off, but my comparative physiology is not the

01:18:13.880 sharpest. So don't trust me there. That's a great description of the microanatomy.

01:18:18.820 And I want to remember- Let me finish the speed thing,

01:18:20.840 because this is what actually happens. Oh, okay. Yeah, yeah, yeah.

01:18:22.180 So what determines the speed? So on those little myosin, where it kind of connects to the actin,

01:18:29.260 it's called the myosin head. Now, a part of that is a bunch of stuff that you guys don't need to

01:18:33.500 know about, but a part of that is called the heavy chain. So there's a light chain portion

01:18:37.140 and a heavy chain. On the tip there, the way that we get a muscle to contract is ATP.

01:18:44.160 So what happens is the myosin are kind of loosely connected to the actin at all times,

01:18:48.940 but in order for it to grab and pull, you need a strong connection. And for that connection to

01:18:53.080 happen and for that to be able to pull it together, it requires energy. So pardon the somewhat crude

01:18:58.700 analogy, but the way that it kind of works is if you imagine cocking a pistol. So in order to

01:19:05.820 actually cock the pistol versus fire the trigger, squeezing the trigger, it takes a lot less energy

01:19:11.580 than cocking it back. If you've ever cocked a thing, like actually you have to pull pretty hard.

01:19:15.180 So the energy that we need actually from muscle contraction is not the pulling together.

01:19:19.900 That's actually almost passive. It is the cocking back part that takes energy. And so that energy

01:19:25.360 comes from ATP. So on the little tip of that myosin head is an enzyme called ATPase. As you know,

01:19:31.280 you hear ACE, you think kinase, like you think something enzyme that's going to work. That's the

01:19:35.820 molecule that hydrolyzes ATP. What's ATP rather. So to make that simple. So what you have to do is

01:19:41.580 actually invest in ATP. That gives you energy, use that energy to cock that myosin back into place.

01:19:47.020 And now it's kind of sitting there, but it can't bind strongly until calcium comes into the picture.

01:19:52.140 It gets released from the sarcoplasm reticulum. That has to come to the equation. It has to cause

01:19:56.740 this conformational change and actin and move these T-tubules or that comes from T-tubules and move

01:20:01.460 some other things around. Once those things get moved around by the calcium and the myosin is like,

01:20:06.760 oh, boom, it connects something. And then it just almost subconsciously snaps as hard as it possibly can.

01:20:10.940 And that's why you can't regulate force production. It's like, it's just going to catch a snap in order

01:20:14.920 for that to go back. You actually have to invest more ATP. This is also side note, what explains

01:20:20.160 rigor mortis. So this happens, it gets contracted. You don't have the energy to then pull it back in.

01:20:25.600 So then you stay in this locked skeletal muscle contraction position. So now the speed at which

01:20:31.900 you can do that, that ATPase thing, that's what determines single muscle fiber contractile speed.

01:20:38.480 That's also that myosin heavy chain is what we measure in the lab. And that's how we determine

01:20:43.340 fast switch versus slow switch. So if you were to use a technique we use called gel electrophoresis,

01:20:48.900 basically you put a gel between two pieces of glass and you just pour gel in there and it gets

01:20:54.380 like solidified, just like hair gel, like a little bit thicker. And then you put each individual muscle

01:20:59.240 fiber in its own vertical lane. And then you put a little bit of positive charge on the top end,

01:21:05.040 a little bit of negative charge in the bottom end or inverse, it doesn't matter. And then you

01:21:08.720 actually put a little bit of chemical bath around the muscle fiber that has a charge.

01:21:12.560 You turn the electricity on, positive goes to negative, et cetera. And so those fibers run down

01:21:17.800 vertically through the gel. We hit stop at a certain time point and the smaller ones have gone further

01:21:23.920 because smaller molecular weight will go through the gel faster. And so we stop, we develop it like you

01:21:29.340 develop a picture, like old school photography stuff, literally the same silver nitrate, et cetera,

01:21:35.060 that you use. And we can see the ones that have gone further down are slow twitch. The ones that

01:21:39.680 stay up higher are fast twitch. And of course we use molecular weight markers to confirm all that,

01:21:44.480 but that's the fact that we're looking at. So what that means is the myosin heavy chain molecular weight

01:21:49.300 determines fiber type and that regulates its twitch ability. The more of those and the faster those

01:21:56.080 heavy chains work, the faster ATPase can operate, the faster the whole thing can contract, the faster

01:22:01.880 the muscle fiber contracts. And there you go. And that's why muscle fiber type is not predicated on

01:22:06.320 the size. It is specific to either metabolic abilities in the old days or now more specifically

01:22:12.420 twitch velocity. So I guess all of this now brings us back to a better position in which we can

01:22:18.680 understand the biopsy studies in these identical twins. If you look at the fiber profile of the untrained

01:22:23.840 twin, it lines up very close to what you'd see in a textbook. So it was around 50% slow twitch

01:22:28.300 and about 30% of these fast twitch 2A form, but then about 20 or so percent in this hybrid format.

01:22:34.520 2A or 2X?

01:22:35.280 2A. So here's one of the things that's interesting. When you get into the 2X conversation,

01:22:40.780 there are clearly, humans have the ability to express 2X. It's just extraordinarily rare.

01:22:47.900 And so what tends to happen is this. If you find somebody that has what we call pure 2X fibers,

01:22:53.000 so these are single fibers that are expressing only 2X, a couple of things have happened.

01:22:58.100 Number one, they've probably had that muscle fiber de-innervated for decades. That's really

01:23:03.080 the only time we see it. In fact, if you look at spinal cord injury folks who had a de-innervated

01:23:07.060 thing for decades, they're as high as 50% or 60% of their total fiber type being 2X. And so this seems to

01:23:14.980 be the default strategy of if you don't activate or utilize the muscle, it eventually is going to fall

01:23:21.320 to 2X. Why? We have absolutely no idea. I could guess, but we don't seem to know. We see it sometimes

01:23:28.680 in older folks, but even then... Sorry, 2X is the hybrid, single fiber hybrid?

01:23:34.020 2X is a pure fiber type. It is the ultra fast. It is the one. So any hybrid is going to be called

01:23:42.140 something like, there is a 1-2A hybrid, there's a 2A-2X hybrid, and there's even a triple hybrid 1-2A-2X

01:23:50.940 that has all three fiber types in the same cell. Those are fairly uncommon. A 1-2A hybrid and a 2A-2X

01:23:58.160 hybrid are very, very common. A pure 2X by itself, though, is extraordinarily rare. In fact, we've

01:24:05.080 done hundreds of thousands of individual fibers in my lab and have probably seen in total 20 or 30

01:24:12.400 pure 2X fibers. You're talking generally something like 0.1% of fibers, something like that, are pure

01:24:19.020 2X. Now, if you dive in literature here, you're going to get confused very quickly

01:24:22.360 because a lot of people don't use detailed enough laboratory methodologies to differentiate

01:24:28.700 these. And so they're going to say, oh, there's all kinds of 2X fibers. They're really not.

01:24:32.860 They're very clearly 2A-2X fibers. They just didn't run high fidelity enough to actually

01:24:36.660 differentiate between hybrids. And so you'll pick up 2A-2X fibers as having some portion of 2X.

01:24:43.280 And so it's a difference between does that fiber contain 2X versus is that a purely 2X fiber,

01:24:49.200 which is sort of a semantic difference. But in our world, it's a big deal.

01:24:53.200 If you find somebody with a high percentage of 2X fibers, something odd is going on. The only

01:24:58.160 exception here is there's no data really on truly fast people. We have a lot on powerful people. We

01:25:05.140 have a lot on kayakers and bodybuilders and weightlifters. But as we discussed at the beginning,

01:25:09.360 that's actually not truly... Meaning we don't have data on sprinters?

01:25:13.460 No.

01:25:14.000 Why?

01:25:14.620 Great question. It's hard to get these folks in the lab, I guess.

01:25:17.800 People haven't been interested in it. It's not a thing. We just don't have them. The only thing

01:25:21.640 we have is there's a case study done. I think he still owns a world record. It's not hard to

01:25:26.840 figure out his name, though. I can't technically say it. 110-meter hurdles, I think. And 60-meter

01:25:31.900 hurdles at the time had a world record of both, I think. Still has one of them. He's the only one

01:25:36.480 I know. I was a graduate student at the time, so I didn't run this study, but I certainly had my

01:25:40.200 hands on fibers plenty of times. And he has something like 24% pure 2X fibers. I'd like to see that

01:25:46.180 replicated. So the untrained guy was 50% slow, 30% 2A, 20% hybrid, AX?

01:25:53.700 2A, 2X.

01:25:54.500 2A, 2X, yep. And then what was the trained, cardio-only trained?

01:25:59.260 About 95% pure slow twitch.

01:26:01.900 So right there, you have the explanation for why he was weaker. He just couldn't generate the force.

01:26:08.160 It's a couple of things. So it answers a handful. Number one, do they change?

01:26:12.840 We know this demonstrably.

01:26:14.600 This is highly malleable.

01:26:15.840 Yeah, not even close. We actually know that there's data on nutrition. There's nutritional

01:26:19.640 aspects that will alter fiber-type composition. Anything that's going to go activate PGC-1-alpha

01:26:24.500 and that whole cascade is going to activate and increase associated fibers. This is going to

01:26:28.900 happen. There's actually a study came out very recently on resveratrol doing it. Not in humans,

01:26:33.200 but a very reasonable dose, 5 grams of resveratrol, I think in cattle, which is not that much at all

01:26:39.500 for a 2,000-pound animal, caused significant changes in fiber-type profile. And there's a

01:26:43.440 whole host of nutritional interventions. The question of, okay, does it change the physical

01:26:46.760 activity? It's been answered so many times for so many decades now. It's just very clear.

01:26:52.040 And in our case, okay, how much? How much can it really change an important amount? Well,

01:26:57.460 I don't know what these people's default is because one could argue the untrained guy was

01:27:03.000 actually in an adaptation state. Yeah. He had a higher state. He deviated away from his potential.

01:27:08.740 Right. Because one thing that seems to be very clear is these 2A, 2X fibers are generally

01:27:12.720 associated with poor health. And so we see this concentration go up with any kind of physical

01:27:17.340 activity or space flight. Whereas a 2X by itself- A 2X is basically irrelevant because they just don't

01:27:22.840 exist. If you have them, it's generally bad news. So you don't want to train into them. So the ideal

01:27:28.040 scenario here is 2A. Those seem to be the place you want to train into.

01:27:31.420 If you do any sort of physical training, those hybrids tend to go down, especially 2A, 2Xs,

01:27:36.180 they kind of go away. And so I'm not surprised that the trained individual had none of them.

01:27:40.800 And I'm also not surprised that the untrained ones. So it lined up pretty textbook. So the

01:27:44.000 magnitude of change is meaningful. It's a case study, all that, but it matters.

01:27:50.240 What's your hypothesis if you had a third brother, a triplet, who was a weight lifter or a power lifter?

01:27:57.560 The distinction, I actually don't think would matter a ton. You're going to get the same answer.

01:28:01.500 I would not be surprised if that third was 70% fast twitch, 2A.

01:28:07.180 And 30% type one.

01:28:08.840 Yeah. With probably very few hybrids if they're trained. Now, the one distinction is the 2A,

01:28:12.440 2X fibers tend to be a little more responsive to a little bit of workload. You have to hit sufficient

01:28:18.080 audience to really get them to go all the way away, but it's not that much. So if you're just like,

01:28:22.100 kind of like a laissez-faire lifter, you'll still have something or not, but if you're training

01:28:26.420 seriously, those things are going to be go away. So I don't really think given enough time and

01:28:30.080 exposure, I don't really think that there's a limit to the plasticity among fiber types,

01:28:34.500 even within a normal human condition. Now this was 35 years. So like.

01:28:39.100 Do we have a sense about the window in which you are maximally susceptible to it? So if someone

01:28:45.420 listening to this is 50 years old and they've kind of been sedentary a lot of their lives,

01:28:51.680 but because they listened to this podcast, they've now got the motivation to become big time

01:28:59.200 exercisers. How much can they bend the arc of their fiber curve?

01:29:04.380 So fiber type is actually really quite cool because it doesn't seem to matter what age you are. So

01:29:09.020 training studies in 70 year olds, we see dramatic changes in fiber type in six weeks,

01:29:13.020 eight weeks, certainly. And the magnitude of change doesn't seem to differentiate. In fact,

01:29:17.400 the way that you want to think about this is it's kind of like an asymptote. The less trained you are,

01:29:22.400 the faster things faster, the initial adaptation, the closer to your edge. So if you're a weightlifter,

01:29:28.040 in fact, we saw this differentiated. So with our world caliber lifters compared to national caliber

01:29:33.300 lifters, the world caliber lifters had been lifting at a very high level for like eight or so years,

01:29:38.640 the national caliber had been lifting more like four years. They were close to fiber type,

01:29:44.120 but the national calibers had more faster fibers. So what this tells you is initial changes happened

01:29:49.960 very quickly, but getting from that last few percentage up took years for that second group.

01:29:55.700 But we will see this again, four to six weeks to see a demonstrable change in fiber type composition

01:29:59.960 is, and it doesn't seem to matter with age. In fact, as you age, it probably gets easier because your

01:30:05.540 level of untrained is so high if that situation is there. One other thing I want to ask you about

01:30:10.080 on the microanatomy side, Andy, is you sort of have talked about it indirectly, but if a person

01:30:14.780 hasn't maybe caught it, can you just explain how hypertrophy fits into this? So when a person wants

01:30:21.340 to have bigger muscles, what's happening at the cellular level with their muscle fibers?

01:30:27.040 So there's an interesting discussion here. The easy answer is when we generally say hypertrophy,

01:30:31.960 what we're referring to is diameter or cross-sectional area. And so if you remember,

01:30:35.920 if you think about the muscle fibers being that cylinder, the width of the cylinder just expands.

01:30:41.060 And so that circle gets larger is the way to think about it.

01:30:44.360 And a crude analogy is getting fatter means each adipocyte is getting bigger. It's taking on and

01:30:50.780 storing more triglyceride. Yep, exactly. So from a skeletal muscle perspective,

01:30:55.820 the diameter gets larger. There's actually interesting work. We actually have some tissue

01:30:59.560 on its way to Auburn right now. Because one of the things that's been interesting,

01:31:02.880 it's like a bro science thing for years of sarcoplasmic hypertrophy versus contractile

01:31:08.560 hypertrophy. And so what this is really positing is, is the change really coming from fluid retention,

01:31:14.960 basically, or is it actually enhanced of the contractile tissue, which in this case would be

01:31:20.420 actinomycin? Seems to have some initial work there that's a little bit of both,

01:31:24.120 and it happens at different phases of training. Is the question, do different types of training

01:31:30.380 increase sarcoplasmic versus contractile hypertrophy? Or is the broader question,

01:31:35.820 hey, is a bodybuilder a bodybuilder because their sarcoplasmic reticulum is huge,

01:31:43.180 but their contractile units are not that much bigger than the average person? I want to make

01:31:46.560 sure I understand the question. So it's close, not the sarcoplasmic reticulum. It's what we call

01:31:50.840 sarcoplasmic hypertrophy. So this would just be an increase in diameter with additional fluid

01:31:54.820 intake. So it is close to what you're saying now. So in other words, does this thing even exist?

01:31:59.720 In other words, or is all increases in muscle size through strength training, assuming it's like a

01:32:03.520 normal positive adaptation, not some sort of weird thing. Is it actually happening because myosin

01:32:08.500 and actin are getting thicker? Remember, you can't add actin.

01:32:11.220 I got it. Okay. Wait, that's amazing. We don't know the answer to that question yet?

01:32:14.540 We don't. More data have started coming out. But even a few years ago, the idea that

01:32:19.500 sarcoplasmic hypertrophy was a thing was thought of as like garbage row science.

01:32:23.840 Meaning the idea, the assumed belief was anytime muscles got bigger, they were getting bigger

01:32:29.800 in the contractile units? Correct. But...

01:32:33.500 By the way, I'm not shocked that that was the default hypothesis. I'm shocked that it wasn't

01:32:37.820 definitively known. It was a technology issue. It was an assay problem. Like figuring out how to

01:32:43.240 actually measure this. When you take a muscle fiber out of a human... Even with an electron microscopy,

01:32:47.740 you couldn't do this? That's not the problem. It's the standardization of fluids. That's the

01:32:51.580 issue here. When you sample the tissue, it's how do you lock the fluid into place, basically?

01:32:55.160 Correct. How do you take this cell out of a living human, get it into some Petri dish...

01:32:59.460 And preserve its fluid architecture without contaminating it. I got it. And you couldn't

01:33:03.620 do that with like liquid nitrogen immediately?

01:33:06.260 That flash freezes. So if you get crystals in there, you actually lice.

01:33:09.360 You screw the whole thing. Got it. Just because I'm such a freaking nerd, I can't stand it.

01:33:13.760 How did you guys solve this problem? Well, I didn't solve it. First of all, Mike Roberts

01:33:17.720 out of Auburn has produced a lot of really interesting work in this area. His labs is

01:33:22.100 extraordinary. But they just figured out they were able to kind of take an assay from a colleague of

01:33:26.300 his, figure out how to preserve it in liquid nitrogen is actually fine. But then from there,

01:33:31.260 you have to thought correctly and you have to do it. So he troubleshot this whole thing for a couple

01:33:35.600 of years. You accept the crystals that'll blow up the size because of course...

01:33:39.760 If you freeze them correctly. Yeah. It's how you thought.

01:33:42.600 Chemistry is hard. I like this. So it gets very detailed, but Mike could give you a better...

01:33:47.380 And I hope there's some high school, college kid listening to this who's studying chemistry,

01:33:51.740 who's realizing just how cool and interconnected all of these worlds are. Chemistry, biology,

01:33:57.940 physics, they're just so linked.

01:33:59.600 I always joke that like, there's only one thing in this world. There's only one science. It's just math.

01:34:03.840 As much as I hate math, chemistry is math. Energy is math. Biomechanics is math. It's that.

01:34:09.760 Math and reductionism, but that's it. Those are two things. So to go back, what the question is,

01:34:14.740 here's where the exercise scientist comes in. Why is it a bodybuilder can have more muscle,

01:34:20.920 yet they're not stronger than a strongman or a weightlifter? Like how is this actually happening?

01:34:24.920 This is where this whole thing comes about. Like how is it that my hypertrophy can exceed yours,

01:34:29.920 but somehow your strength? And the easy like sophomore answer is all neurological adaptations.

01:34:35.820 Okay, fine. Sure. But like there's nothing happening intracellularly. Well, I don't think

01:34:40.260 that's correct. And in fact, it doesn't look to be the case. And so there is some sort of

01:34:44.700 combination because here's the juxtaposition. There's a thing called lattice spacing, which is

01:34:48.740 there's an optimal distance between that myosin and an actin. In other words, if I was trying to

01:34:53.880 produce a powerful contraction, but I was butted up next to each other, I can't actually squeeze that

01:34:58.260 hard because there's nowhere to go. If I'm too extended, then I actually can't.

01:35:02.100 So it's the same idea as preload in a heart.

01:35:04.320 A hundred percent. Preload is going to determine stroke volume, everything incoming in. So this

01:35:08.660 spacing, if you're going to start adding contractile units one way or the other, you have to preserve

01:35:13.580 spacing somehow. The idea is it will exceed, it will expand hypertrophically only to the level-

01:35:20.060 But if it actually compromises your, going back to math, I promise you there's a mathematical

01:35:25.480 optimization for the exact strike distance between actin and myosin to not be overextended or

01:35:32.600 underextended and to have that perfect preload for maximum contraction.

01:35:36.840 A hundred percent.

01:35:37.380 And if your hypertrophy train, this is now I'm totally making this up, but if your hypertrophy

01:35:41.040 training interfered with that and compromised it, you might gain size at the expense of potential

01:35:47.080 strength.

01:35:47.540 Right. Or if that hypertrophy was coming simply from excessive fluid and not actually contractile units,

01:35:53.060 then you would actually have a larger muscle. And when I say fluid retention, I'm not talking about

01:35:57.680 like acute fluid retention. I'm not saying like you're bloated today, you've water loaded.

01:36:01.920 I mean, there's enhanced fluid and a homeostatic balance inside the tissue because diameter has

01:36:08.060 gotten larger, but it wasn't met with an equal amount of increase in contractile units. So if that

01:36:13.260 number gets off.

01:36:14.080 Yeah. I think another physiologic point that's worth explaining to people is how much people are

01:36:18.200 familiar with the idea that two thirds to 70% of our weight, I stood on the scale this morning,

01:36:24.220 that number on the scale, two thirds to 70% of it is H2O. And then people say, okay, well,

01:36:30.800 how can that be? Because I get that my blood plasma is water. That can't be where it all is. No,

01:36:37.420 most of it is in the cells of our body. And the muscle is of course, no exception,

01:36:43.240 given that it's such a ubiquitous cell. Totally. And in fact, given that it occupies the vast

01:36:48.280 majority of mass in your body and giving the fact that in order for it to store its primary

01:36:52.580 unit of energy, it needs to bring water with it being glucose. That's going to pull the pain.

01:36:56.640 And just tell folks how that differs from, again, going back to bodybuilding. I love following Jay

01:37:02.780 Cutler on Instagram because I was just such a fan of his as a bodybuilder. And he's just one of

01:37:07.560 these guys who in retirement is still training hard, paying attention to his nutrition. It was an

01:37:13.080 interesting video. So he went into like In-N-Out Burger and he was like, it's my cheat day. Today,

01:37:17.100 I'm going into In-N-Out Burger. And he places this monster order. What caught me was how much

01:37:23.200 he said, no salt, no salt, no salt, no salt. So he was like two burgers here, fries here,

01:37:28.460 but no salt, no salt, no salt, no salt. Clearly this guy knows something about the effect of sodium

01:37:34.240 on fluid retention. That's a different fluid than what we're talking about now.

01:37:39.200 Yes and no. In the sense of like, he probably has an either direct or indirect understanding,

01:37:43.080 if you smash down seven grams of salt right now, bad things are about to happen in a lot of areas.

01:37:49.520 Like more specifically, if you just look at, we're getting maybe after, but if you look at hydration

01:37:54.420 and dealing with the athletes that I deal with, a weight cut is a huge deal. Managing a 15 or more

01:38:00.700 pound reduction in water over a course of 48 hours and then putting that back in. If you don't

01:38:06.280 understand being hypoosmotic or hyperosmotic or isoosmotic, like you're going to cause a whole

01:38:12.420 host of problems from kidney issues to diarrhea, to bloating, to all kinds of problems. So you have

01:38:18.820 to actually understand what you put back in them has to be the same thing as what's intracellular or

01:38:24.880 there's going to be a huge shift. You're not going to drive fluid into tissue and you get into

01:38:28.480 situations where guys are peeing and girls are severely dehydrated. They're peeing yet.

01:38:33.100 They put very little fluid actually back into tissue because blood volume got so large, it expanded

01:38:38.120 so quickly. They have a sense to excrete because total volume gets too high, quote unquote, but they

01:38:43.100 didn't actually balance electrolytes. And so nothing goes intracellular, which is where you're trying

01:38:48.480 to get it to outside of organs. Once your organs have functional organs, rather, as every group.

01:38:53.000 And are there any rules of thumb on that? We were talking before the podcast started how

01:38:57.380 I had food poisoning. And in a span of like two days, I lost seven pounds and my weight is about

01:39:05.020 the most stable metric in my life. It just doesn't fluctuate a pound. So to lose seven pounds in two

01:39:10.120 days, basically due to the fluid losses of being sick and having to go to the bathroom about every

01:39:15.540 seven minutes, coupled with not really wanting to eat during that period of time. What is your best

01:39:21.000 guess as to, I mean, let's just posit that much of that seven pounds, six and a half of it is water.

01:39:27.820 What's the ideal strategy to replenish that in terms of hyper, hypo or iso osmotic? If I'm going

01:39:36.020 to try to replenish that in the form of liquid. Handful of things. Number one, you need to go

01:39:40.020 slowly. So you got to make sure that you don't get excessive. So I don't want to pound four liters

01:39:45.700 worth of four grams of sodium in the first six hours. I'm feeling better. Yep. So number one,

01:39:51.680 you want to shoot for something like the neighborhood of 110%, 125% of fluid.

01:39:57.380 Well, wait, cause you're going to lose something. That's going to happen. So let's say you lost

01:40:01.800 seven. My brain is like, okay, we're going to go to eight and a half, nine pounds, something like

01:40:06.920 that. You want to round this and call this a gallon. Okay. We're at a gallon. All right.

01:40:10.200 We're going to bring that in over the course of three hours, maybe four or two gallons, right?

01:40:14.060 Well, four liters in a gallon ish, a little over change, two point. So a couple of gallons.

01:40:18.840 Yeah. I mean, a gallon is four liters, a liter is a kilo. So you're talking four kilos.

01:40:22.960 You could do that over two days.

01:40:24.380 No, like three hours.

01:40:26.100 Oh, you could.

01:40:26.880 Oh yeah.

01:40:27.600 Once your GI system settles down. So you would have fighters that would, I guess they have to,

01:40:31.780 if they're going from a way into competition, they've got to bring that in.

01:40:35.060 For sure. Last week, guy in Abu Dhabi weighed in 136 pounds. There's 152 pounds within probably

01:40:40.600 five hours.

01:40:41.880 And what was the osmolarity of?

01:40:43.960 With no urine, no diarrhea, no GI, none of those things.

01:40:47.120 What was the osmolarity of the fluid he took in?

01:40:49.080 So it depends the guy going through it this week as well. We actually measure that. So we actually

01:40:53.920 will measure, run a basic sweat test and you can figure out sodium concentrations. And then

01:40:58.500 the amount that they get back is actually dependent upon them. So that number can fluctuate depending

01:41:04.280 on if they're a high salt, low salt sort of sweater. It also depends on how much salt we've

01:41:08.520 had to pull out the week of or not. Obviously we don't pull out salt five or six days away or like

01:41:14.380 anything bananas like that. But if you have seven to 8% of your body fat, you have to lose or sorry,

01:41:20.760 seven to 8% of body fluid of your body weight and fluid, you have to lose. We're going to take

01:41:25.680 some salt out for a couple of days just to get us down there.

01:41:29.040 And salt out, tell me how many grams per day they're down to in sodium.

01:41:32.860 Zero. You're going to get down to zero on those last couple of days. So you're going to get down to

01:41:37.360 like a classic example is we might have them at like two and a half grams, kind of like fight week

01:41:43.300 per day. It's like not unreasonable, but the day before water cut day, it's zero. It's as much as

01:41:49.060 like you're boiling chicken to get as much possible stuff out of there. You're eating as much as close

01:41:53.820 to zero as we possibly can for that 24 hour period. If you have to go there, ideally you don't have to

01:41:58.480 go that low, but sometimes you have to. That's a bigger impact than cutting calories, which you

01:42:02.580 don't really want to do at that point. Calories are irrelevant at that point. It is simply physical

01:42:06.700 weight of food. And this is a fluid manipulation game. If we can keep them at like a gram

01:42:10.980 to that last day, like cool. But a lot of the times you're staring down the barrel of

01:42:14.920 an eight to 15 pound water cut on a day. You just need every advantage possible.

01:42:20.560 Wait, wait, wait. I'm sorry. Eight to 15 pounds of water you can cut in a day?

01:42:24.780 Yeah, for sure.

01:42:25.660 In a guy that starts out as little as like 160 pounds. If you're trying to get 160 to 147,

01:42:31.440 you're doing that in a day?

01:42:32.920 You can. It's not ideal, but you can. For sure. You could do that in half a day.

01:42:36.320 Okay. Let's make it ideal. Would two days be ideal to do that?

01:42:39.900 So ideally in the situations, you come into fight week in the proper situation. So you need to come

01:42:46.480 into fight week, hydrated on normal, or like even maybe slightly higher salt, normal or higher

01:42:52.280 carbohydrate. You need to come in healthy. You need to come in recovered, not over-trained,

01:42:56.060 all that stuff. Like you have to play a whole bunch of games here. Monday through sort of Thursday,

01:43:01.960 you're going to start getting as much of this off passively as you possibly can. And so you're going

01:43:06.340 to typically keep carbohydrate very low, 50 or less grams, sort of depending on what they're doing.

01:43:11.700 And you're going to deplete glycogen. That alone is going to start helping you pull some water.

01:43:15.020 And so you're going to passively do it. You can play games with fiber. And so you have these low

01:43:19.560 residue diets the last couple of days. And so you can make sure you're not holding onto food in your gut.

01:43:23.560 That can buy you a couple of kilos, depending on the size of the person. And so ideally,

01:43:30.280 for example, if you came in Monday, a fight week at 170 pounds, hopefully we can kind of get you down

01:43:35.820 to like 164, 165 by Thursday.

01:43:41.780 Just passive stuff.

01:43:42.700 Yeah. And now you're talking like we've got nine to do over 24 hours. Well, you're going to float a

01:43:47.280 couple throughout the day, just urinating and stuff because you're being very hydrated. You're going to

01:43:51.720 float one or so overnight because of that. So really there goes three right there. So now you're

01:43:57.420 talking like we've got to do six or seven of like active water dropping in that situation. So that

01:44:03.380 really is a 15 pound week, but it's not that bad. Those six come just from taking, that is this

01:44:09.500 sodium, complete sodium restriction. You're going to have to add in some sort of sweating component.

01:44:14.000 So you're going to have to do something like that. The ideal situation is you do a little bit of

01:44:20.740 physical activity, maybe to burn any last little bit of glycogen without getting too terrible

01:44:25.120 feeling. And then from there, you see a lot of what's called a mummy wrap. So you basically lay

01:44:28.940 down and you put a bunch of blankets on yourself. It's like very easy to regulate blood pressure

01:44:33.840 and make sure you're okay. You're not at a risk of passing out. You'll sweat like a pretty good

01:44:38.120 amount like that.

01:44:39.160 And then weigh in is Friday morning, nine o'clock in the morning. Usually a lot of times, if we actually

01:44:44.600 do this best, you don't do much without the night before you wake up the next morning and you're

01:44:49.400 say four pounds over, and you can actually sweat out four pounds pretty easy in a sauna, 20, 30

01:44:55.540 minutes, 20 minutes in a sauna, 10 minutes on down. And then fight is Saturday night. So you've got

01:45:01.060 18 hours plus to put it back on.

01:45:04.000 More like 30, 36, because they're going to weigh in at nine o'clock in the morning, Friday.

01:45:08.620 And typically if we do this again, correct. All these scenarios don't always play out, by the way,

01:45:13.100 it can get quite chaotic. You would ideally be back to your normal Monday weight within four to five

01:45:18.460 hours after that weigh in. And so you're only touching that final scale number for a very

01:45:23.700 short amount of time. You're kind of faking the scale. So you're back to that normal fight

01:45:27.520 number by the next morning. Like you're certainly well back normal. Now the only difference, the only

01:45:33.920 thing here is recovery muscle glycogen in 36 hours is close enough. If you do this correctly, you can

01:45:39.960 get a pretty good way. You can actually get body weight back. No problem. The difficult part is

01:45:45.100 getting brain fluid back. I'm not totally convinced that gets all the way back in 36 hours.

01:45:51.040 So that's the like little bit of a challenge that you have, but there's just no way around that.

01:45:56.120 So is there an advantage to be made for a fighter who I'm just making up the weight of 147, but just

01:46:01.300 pick a weight to live, train and show up at 150 instead of 160. So that, okay, the drawback is he's

01:46:10.420 going to be in the ring at less weight, but the advantage is he went through less metabolic fluid

01:46:16.480 shift in the two days prior, and maybe he's actually just physiologically better.

01:46:22.440 So there's actually a good amount of research on that, of looking at exactly what happens,

01:46:26.140 then doing performance testing pre and post. It's not that bad actually from a performance

01:46:30.580 perspective, as long as you stay within certain range. If you get excessive, then yeah. There's been

01:46:36.520 a number of folks follow the UFC. Look at Frankie Edgar. He's won multiple world championships,

01:46:41.360 significantly undersized. So that works. In general though, it starts to become challenging

01:46:46.700 because in the sport of MMA, the weight classes are so large. In boxing, you've got a weight class

01:46:51.900 every four to seven pounds. So if a guy is really six pounds heavier than you is with that big a deal

01:46:56.860 in boxing, no. If a guy is 15 pounds heavier in a grappling sport, and you'll see this like he

01:47:02.460 held me against a cage. I couldn't, she just held me down. She didn't even be. Ideal situation is

01:47:06.820 nobody cuts weight. Ideal situation is that's all gone. But how do you ever do that? Because somebody

01:47:12.180 will be like, well, I'll take that advantage. So ideally, if you do it right, and you can come

01:47:16.620 into fight week at 6% over fight weight, it should be no problem. Performance wise, you should get there

01:47:23.100 other than like the pain in the ass it is to deal with. You start getting to 8% fight week. Okay, it's 10%

01:47:29.260 fight week. Like it's going to be really, really challenging. All right, let's bring this all back.

01:47:34.960 We've gone probably a lot deeper into the physiology, the anatomy, the micro anatomy of the

01:47:40.060 muscle. But I think it's worthwhile. I think this was an investment that was worth making, because now

01:47:45.820 it becomes a lot easier to talk about some of the things that are effectively the application of this.

01:47:52.700 And I really want to kind of go back to how we started talking about this, which was through the lens

01:47:58.640 of different types of athletes that are effectively the beacon of excellence in anything that has to do

01:48:09.780 with muscle. So we talked about a power lifter. Power lifter, despite the bad nomenclature,

01:48:16.880 is ostensibly the strongest athlete at the all out max one rep, don't care how long it takes

01:48:24.800 movement. You then go to that weightlifter who's also doing a one rep. But boy, he or she is also

01:48:32.640 got to be incredibly coordinated. And therefore, by definition, because of the nature of the movement,

01:48:38.500 incredibly explosive, but it's just one rep. The strongman, he's throwing boulders and having to

01:48:45.920 pick them up and throw them again and again, again, insane amount of strength. But you're not just relying

01:48:51.440 on one energy system. You've got to also have a little bit of endurance, both muscularly,

01:48:56.380 cardiovascularly. The CrossFit athlete, also very strong, also agile, mobile, has the explosivity,

01:49:05.040 but not basically isn't as good at anything as those first three, but has something that none of them

01:49:10.600 have, which is a greater degree of endurance. I think we looped in the bodybuilder, which aesthetically

01:49:16.400 looks like better than all of them, has bigger muscles than all of them, but has to meet no

01:49:21.340 other requirement. And then I think I like that you brought in finally the sprinter, which is the

01:49:27.520 pure, you could argue the highest ratio of power to weight and locomotion optimized. Okay. I will never

01:49:37.820 be half as good as any of those six. And most people listening to this don't need to be,

01:49:43.680 but we probably want bits of each of them in us, right? So let's now talk about hypothetical ways

01:49:51.080 to train. And I did this with Lane and people really liked this approach. So maybe we'll try

01:49:57.620 to do the same thing. Let's go through some hypothetical case studies, right? So person

01:50:01.220 comes to you and says, Andy, I want you to design a training program for me. Here's what I look like

01:50:06.280 now. Here's what my goals are. And the goal is a no holds barred approach to what they need to do.

01:50:14.000 In other words, unless I specify it as part of the problem, don't hold back. So we'll start with the

01:50:19.260 easy one, which is the untrained individual who comes to you and says, okay, I bought it. I'm all in

01:50:27.440 on this. I'm willing to go to the gym. You know, Peter's already got me doing a couple hours a week,

01:50:32.220 a zone two on the bike, but I don't even know how to approach this strength training thing.

01:50:37.740 I'm willing to put three hours a week in the gym. I want to get bigger. I had a DEXA scan

01:50:44.420 and it really showed that my ALMI was about the 40th percentile. And looking at the literature,

01:50:51.640 I think being at or above the 75th percentile for lean mass is a better place to be. So that's where

01:50:57.080 I'd like to be in a year, two years, three years, but I also want it to matter. You know,

01:51:01.780 I want to be stronger. I want to be able to do stuff when I get older. I don't just want to get

01:51:06.320 bigger. I want to be able to never enter a competition. I'm not here to enter the strong

01:51:10.780 man competition, but like, I never want to hurt. I want to be able to chop wood in my backyard.

01:51:16.260 I want to be able to carry stuff around. I want to be able to travel with a backpack on.

01:51:21.320 Any other questions you have for me before you design my program, Andy?

01:51:24.020 How many days per week did you say? I could be up to going into the gym,

01:51:28.000 like three days a week, an hour at a time. Three days total. Okay, cool. So you've basically

01:51:33.800 described every one of our executive clients in our rapid health optimization program. So I can nail

01:51:39.540 this one. Obviously at most of my career with professional athletes, but we deal with this

01:51:43.980 problem all the time and rapid. Here's what I would say. You've already got zone two stuff

01:51:48.240 knocked out. That's steady state. Here's what you need to pay attention to. You described muscle

01:51:52.760 was insufficient. So we got it in our brain, we're automatically thinking we've got to put

01:51:55.920 on muscle mass. You also said they're untrained though. And one of the things you're going to

01:51:59.260 see is quite clearly. Oh, sorry. I sort of left out. I was active in high school and college.

01:52:04.280 It's not like I've never done anything, but you know, I've been working really hard at my job,

01:52:09.280 started a family. And so for the last 10 years, my only exercise has been activities of daily living,

01:52:16.260 which includes sometimes hiking and playing with my kids. I haven't been in the gym.

01:52:19.800 Yeah. Perfect. You still described everybody in rapid health optimization, right? No problem.

01:52:24.460 So I'm just going to walk you through, I'm going to break the fourth dimensional wall here.

01:52:28.780 All right. We need hypertrophy. This is the base and foundation of everything. You're going to get

01:52:32.840 stronger by doing hypertrophy at this stage of your training. Like we talked earlier, those are not

01:52:37.840 always coupled. You can get stronger without getting more muscle mass very clearly. And you can get

01:52:42.960 really a lot of muscle without optimizing strength. We talked about that at the end of those spectrums.

01:52:47.680 You're at this end of the spectrum, the opposite. Those are going to be basically linked at this

01:52:52.000 phase in your training. So we don't have to do both. You can do one and get both adaptations at

01:52:56.720 the same time because I'm so low on the curve. Anything is going to give me a bit of, in fact,

01:53:02.080 we can get that from not even lifting weights because in fact, of our training studies, you'll see that

01:53:06.960 equal adaptations and muscle size hypertrophy from even steady state cycling. Initially for six to eight

01:53:13.820 weeks, you'll see equal all of our concurrent training models and studies show the same thing.

01:53:19.020 Like not only is there not an interference effect at this stage, it's a complimentary. In fact,

01:53:22.860 a study came out more recently showing six weeks of endurance exercise, steady state cycling prior to

01:53:28.240 hypertrophy actually enhanced end result muscle growth. So spending time initially getting physically

01:53:35.260 fit before trying to add muscle mass for someone like this, it's a very fruitful investment.

01:53:40.400 So the fact that I've been doing my zone two for two months actually has you pretty happy.

01:53:45.520 Super happy. Okay. I'm also thinking, all right, you mentioned longevity, physical function as we

01:53:51.940 move down. You also mentioned, you said three years from now or something, which tells me your mind is

01:53:56.780 really thinking about long-term investment here.

01:54:00.180 That's right. Peter has me committed to, this is not about looking good in my bathing suit in six

01:54:05.500 weeks. I'm not in a rush.

01:54:06.700 So one of the things that you'll see very specifically with aging is a loss of physical

01:54:12.100 function. And that's more geared for power. In fact, the rate of, you've probably covered this

01:54:16.840 before, rate of loss of muscle mass as you age is something like a half to 1% per year. Loss of

01:54:25.300 muscle strength is double to triple that. Loss of muscle power is triple that. And so what are you

01:54:31.620 seeing? You see a very precipitous drop in muscle power. And why is that happening? A little bit of

01:54:37.500 loss of speed. Aha. So preserving, in fact, you can do this. You can go look at the world records

01:54:42.700 of all sports across age groups. So if you look at like track and field, what's the world record in

01:54:48.500 the hundred meter dash? And what's the world record for the 30 to this? What's the world record for the

01:54:53.260 40 to 50 year old range, 50 to 60? And what you'll see is strength sports like powerlifting.

01:54:58.660 The world record through age doesn't go down that much. The world record in speed and jumping sports

01:55:04.940 just falls off a cliff. So it's preserving speed. In addition, my friend, Greg Grosicki,

01:55:11.040 just published a paper this week in a journal of physiology, a blue ribbon journal in our field,

01:55:15.700 right? As high as you get. And this was actually looking specifically at single fiber contractile

01:55:20.200 function changes with aging. And the data here are extraordinarily clear. I've been a long run.

01:55:25.160 You see very little loss of function in slow twitch fibers through aging, regardless of exercise or not.

01:55:31.180 I sort of mentioned this earlier, but you see a dramatic reduction in fast twitch fibers.

01:55:36.400 And you actually don't see a drop of power. And so there's nothing internal to the muscle fiber

01:55:43.040 that's going down. So another way to say this is if you take an individual muscle fiber loss,

01:55:47.400 that's the problem. It's the fiber size. The atrophy of fast twitch fibers is the almost

01:55:53.580 exclusively the problem with aging and muscle. You have got to maintain fast twitch fiber size.

01:55:59.980 Now there are some loss of total fibers, but that is actually very difficult to find scientifically

01:56:05.060 counting total amount of fibers in a live human muscle is extraordinarily difficult.

01:56:09.600 Really what we're after here is anytime I'm thinking longevity, I'm thinking primarily absolute

01:56:16.360 force and power has to be preserved. And it's, this is a fast twitch fiber atrophy issue. This is a

01:56:22.400 target. So these are the things spinning in my head. So how is this three day a week

01:56:25.980 combination at all?

01:56:28.020 Just to make sure we translate that Andy, because I think that was so important. What you just said,

01:56:32.460 you're basically looking, I'm 50 and you're looking down the barrel of my life saying,

01:56:37.920 you want to live another 40 years and you want to be functioning. The most important thing I can do

01:56:43.840 for you in the gym is not focus on the things that you're going to get for free. It's focus on the

01:56:50.180 things that are declining so rapidly. And I will, as a corollary to that, get a bunch of other stuff

01:56:57.040 for free, but I have to focus on the atrophy of your fast twitch muscle fibers because it's already

01:57:03.720 happening and we need to stave that off and we need to put in the gym systems to support the reversal

01:57:11.460 of that process. Because if I just ignore that, I might as well be that highly exercised twin guy

01:57:17.500 who's doing all his cardio, but at the end of the day, he can't jump off the curb. He's going to be this,

01:57:23.200 the hyper cardio athlete, who's still a decrepit person in the last decade of their life.

01:57:29.180 To make it even better or worse, those fibers require specific types of training. Unless you

01:57:36.860 specifically do that, you just don't have any chance of those tissues. The other tissues aren't as

01:57:42.580 like hypertrophy. Hypertrophy is pretty nonspecific in terms of your training application. But if you

01:57:48.300 want to make sure that you're targeting fast twitch fibers, like this requires very specific protocols

01:57:52.680 or like you have no chance. Fast twitch, slow twitch fibers are going to get activated with any activity

01:57:57.140 of daily living. They're going to get activated with any amount of physical strain, whether you're

01:58:00.820 doing intervals, zone two, zone six, that doesn't matter. Zone 28, pick whatever you want,

01:58:05.600 slow twitch are good. It's the fast twitch fibers that require intention. And that's why I make such a

01:58:10.700 big deal of it because you can't accidentally get those. It's sort of like what we say in fighting is

01:58:14.940 you can sometimes accidentally knock somebody out. There are fluke punches. There are no accidental

01:58:19.660 submissions. There's no fluke arm bars. Like you have to know what you're doing there or not. So

01:58:24.920 coming back to our avatar. By the way, I love that line because I often say that to especially my

01:58:31.080 female patients who are completely untrained, borderlining on cachectic, afraid of lifting

01:58:36.980 weights. They just want to do yoga all day. And when I say, look, we have a problem here. You're

01:58:42.520 osteopenic and you're so weak. I am worried for your life. And they say, I just don't want to lift

01:58:49.540 weights because I just don't want to get too big. And it's like, I have good news for you. The myth

01:58:55.260 of accidental muscle has been fully debunked. Fully. Me and every other guy out there can tell you

01:59:02.220 we're waiting for it to happen. It hasn't happened. The odds that you're going to wake up and think,

01:59:08.620 God damn it, I'm too muscular. It just won't happen. The vast majority of us sitting around

01:59:13.880 hoping and praying and devoting most of our waking hours and non-waking hours to this goal that you

01:59:18.420 think might accidentally happen. You're good. You're totally safe here. All right. So we know

01:59:23.860 we have to preserve fast-witch muscle fibers for the long-term. We know we have to take care of VO2

01:59:29.780 max. This is another, I'm sure you covered this in depth, important thing for longevity. All right.

01:59:35.580 But we got some constraints. We also have to be considerate of, I have not trained in 10 years.

01:59:41.480 I'm going to get very sore very quickly. And if I become too sore, that it dissuades further training.

01:59:47.620 Now I'm going to lose you. I bought in, but that shit was too hard. I was so sore. I couldn't even

01:59:52.040 walk. Blah, blah, blah, blah, blah, blah. I think in your show with Holly, she talked about making

01:59:55.880 sure you start with a very low volume, way lower volume than you think. We have time. We just need

02:00:02.480 to move. I'm going to be very cautious of eccentric movements. They will generate more soreness than

02:00:08.320 relative. And the last part before I give you some direct answers is we want to start building

02:00:12.800 movement patterns that we're going to need over time. And so this is an investment. We can get

02:00:18.100 all that done by doing the same sort of training where we're practicing movement patterns. We're

02:00:22.620 getting that stuff groove. So we don't pick up injuries later. We're not getting excessively sore.

02:00:27.040 We're building some muscle mass because we're going to get that anyways. And we don't need to go there.

02:00:30.980 So if this was a six month program, because you can't write the same program for the next 50 years,

02:00:36.360 what's the first six months, I guess, is if that's your question. Zone two is out of the way.

02:00:40.580 I would probably stick to fairly similar to what Holly said initially, which was,

02:00:45.800 okay, something like one to three working sets of probably four exercises a day,

02:00:54.200 something like that. We want to spread those across upper, lower, and kind of some different

02:00:57.960 movement patterns. And we want to practice the compound movements. I'm not going to isolated

02:01:01.700 single joint movements yet. Let's learn how to do a goblet squat. Okay. This is a squat. You're

02:01:07.580 going to hold the dumbbell sort of in front of your chest. Great. We're going to learn to do a hip

02:01:12.180 extension. We're going to learn to do a basic overhead press or some bent rows, things like

02:01:17.200 that. And I'm going to spend 30 minutes on those things. I don't even really care about tracking

02:01:23.700 progression at this point. We're going to track to get the movement pattern down, right? Did you brace

02:01:28.880 as our spine in the proper position? Are you breathing through your nose and through proper

02:01:33.560 positions? Is your neck in the right spot? Great. All this foundational stuff that feels like

02:01:37.740 not a big deal at all right now, because it shouldn't be. But we're making sure boxes are

02:01:41.960 checked so that when we start progressing load later, that neck doesn't start getting irritated.

02:01:46.980 And we're just being in that position. Okay. So we're basically completely optimizing

02:01:51.280 movement patterns. We're making sure we don't hurt ourselves. We're learning new skills. We're

02:01:57.480 learning skills of exercise. Let's now go to the next six months. So I come back to you,

02:02:02.940 Andy and I say, you know, this has been great. Like this is not as difficult as I thought it was

02:02:07.980 going to be. I've kind of enjoyed going to the gym. And honestly, like I even see a little more

02:02:12.340 definition in my arms and my legs and I'm a little hungrier. So I've been eating a little bit more.

02:02:18.480 I haven't lost any weight or anything, but my pants fit a little bit better. I'd like to take

02:02:23.360 this up a notch. I can't commit more time though, Andy, three 60 minute spots is all I can get

02:02:28.860 because I still got to get my kids from school and work is just as demanding as ever. But how do I

02:02:34.120 increase the desire to be even bigger and even stronger and even more functional?

02:02:40.220 So now we have to start investing that 60 minutes in those three workouts into different sections per

02:02:45.320 workout. So we need to start doing something to start addressing power and speed. I'm going to give

02:02:50.780 that the first 10 to 15 minutes though. We don't need to go nuts now, but we need to introduce those

02:02:55.240 movement patterns and those velocities and those tissue tolerance, what we call it. So your ability

02:02:59.840 to land and absorb, it's not creation of power, but it's the backend. How did I stop that movement?

02:03:05.240 How did I land from it? We're going to continue to invest in the muscle growth, but now we can start

02:03:10.220 pushing the pace a little bit. And then we're actually at the end, start investing in either

02:03:14.540 muscular endurance and or interval stuff. So if we're still continuing to do zone two, that's great,

02:03:19.820 but we haven't worked on getting heart rate up, coming back down and regulating that whole piece.

02:03:24.060 So what's that look like? The first 10 or so minutes of all three workouts per week,

02:03:27.980 we're going to do something in basic movement patterns. So let's imagine a box jump. We'll do

02:03:33.220 a box jump. We're going to jump from the ground and land on a box that's say 18 inches in the air.

02:03:37.280 We're going to practice that movement pattern. I want you landing on the box, not on the ground

02:03:41.780 that reduces the eccentric landing because you're going to be absorbing way less. So you're not going

02:03:46.780 to get as sore, but you're going to have to pop a little bit. You're going to have to jump to get up

02:03:51.000 there. And we're bracing that movement pattern. I'm going to probably do something.

02:03:54.340 How are you determining that height, Andy? 18 inches seems really high to me. How do I know

02:03:59.160 if I shouldn't be 12 to start? What level of fatigue? How many times would I do this so that

02:04:03.840 I can gauge how high it needs to be? There should be no fatigue. This is simply about high.

02:04:09.300 This is load tolerance then?

02:04:10.840 Load tolerance and it's introducing power.

02:04:13.200 Okay.

02:04:13.440 So you're going to start learning how to move fast, but you're going to do it in a safe thing

02:04:17.820 where you're not going to pull a hamstring. And just to be clear, Andy, I don't need to

02:04:21.100 compete in sports. I don't play basketball anymore. Are you sure you need me doing this?

02:04:25.260 Because all I'm trying to do is I just want to be able to pick up my grandkids in 30 years

02:04:29.880 or 20 years. Yeah, a hundred percent. So in order to pick up your grandkids, you need to not be in

02:04:34.280 the hospital. You need to be not living in an assisted living home. Do you know what puts people in

02:04:38.520 assisted living home? Falling and breaking the hip. The connection between morbidity and mortality

02:04:43.140 with a hip break is extraordinary after the age of 60. It's not even 90. It is 60-ish. Large reason people

02:04:50.340 fall is they actually don't have foot speed. What do you mean? If you catch yourself, your toe on the

02:04:55.500 corner or you slip, you have to have the foot speed to be able to put your other foot or that foot back

02:05:01.140 out in front of you in the proper position. Then you have to have the eccentric strength to stop that

02:05:07.140 fall. And so I need foot speed to get there and I need eccentric strength to brace the fall so you

02:05:12.280 don't land and break your hip. That's what's going to keep you playing with your kids when you're 60.

02:05:16.640 Capisce? Yeah. Even though I don't want to be a quote unquote explosive athlete, I still have to

02:05:22.200 kind of train like one. In some part. And I'm asking for 10 minutes of your workout. Okay. So I want to

02:05:27.860 keep you there. You can imagine the, I can continue to give you examples and analogies, but this is if you

02:05:33.140 want to go for a hike again and you trip, or you need to be able to get up and do a little

02:05:37.320 scramble. Your 10 year old grandkid is going to want to go up that rock. You got to have a little

02:05:42.080 pop to get up there too. You want to be able to pull yourself like all these things. That's what's

02:05:45.180 going to keep you from going. No, you know, I'll just sit down here and wait. You go ahead and go.

02:05:48.900 Yeah, exactly. I had a patient once say something that I love. I asked him kind of what were his goals

02:05:54.480 for aging. And he said to always be able to go to my kids and grandkids. And he meant it both

02:06:01.400 micro and macro, meaning I never want to be in the position where I can't get on an airplane and

02:06:06.620 travel and go wherever they are. And I never want to not be able to go physically in the moment to

02:06:12.320 where they are. I thought it was just a very elegant explanation. That second part is brilliant.

02:06:17.160 That's so good. Because that's the example there. I'll wait here versus no, I'm going to come with

02:06:20.660 you up that little rock. It's the water slide. It's, I don't want to climb up those stairs.

02:06:25.660 It's seven of them, but like, it's all the little stuff. I have two little kids. So I'm very in the

02:06:30.080 world of like what a four-year-old will do. So what are some other things that we would do

02:06:34.220 in that first 10 to 15 minutes? So I love the idea of the box jump with landing on top. So you don't

02:06:39.280 have that huge, massive deceleration. What about bounds, skips, things like that would all be in there?

02:06:46.160 Yep. Medicine ball throws are great. Medicine ball slams are great. Medicine ball tosses

02:06:50.180 up in the air, high as you can go, as far as you can go behind you. These are reinforcing movement

02:06:55.500 patterns you've built the previous six months, proper hip extension versus low back extension,

02:07:00.540 et cetera. It is also doing what we call triple extension. So you're simultaneously explosively

02:07:05.680 extending the hip, knee, and ankle. And this is a very important human movement pattern. You can do

02:07:10.560 that without jumping and landing by throwing a medicine ball, tossing it. If you go to plyometrics,

02:07:16.520 you have to be a little bit careful here. Plyometrics are totally safe for all

02:07:20.140 ages. As long as you account for volume, you just can't do too many of them at too high of an

02:07:26.500 intensity. In this case, the eccentric load. So jump rope, a five minute jump rope is just

02:07:31.880 plyometrics. When you go single leg to single leg, you start increasing risk. So if you're to jump from

02:07:36.960 your right leg and land on your right leg alone, risk, but two leg to two leg is very easy. For Pete's

02:07:42.520 sake, you can play hopscotch. The hopscotch is just two legged plyometric to single leg to back forward

02:07:48.040 progression lateral. It's a wonderful little exercise. Isn't it interesting when you go to a

02:07:51.820 playground and watch kids play to realize the, they're not being told to do this, just the inherent

02:07:59.240 ability that they have to be explosive. And as you said, how that deteriorates with age, you just can't

02:08:06.720 imagine watching a group of 40 year olds sitting around just deciding, let's go play this fun game

02:08:12.240 where we jump around. I mean, you do that if you're playing a sport, you do that if it's part of your

02:08:16.600 pre-programmed workout, but it's not the equivalent of neat. There's no spontaneous.

02:08:21.860 Yeah. It's not spontaneous. Last one I love is actually don't get thrown off by this word,

02:08:26.220 but I love sprinting. Just give me 70%. You would be surprised of like, Whoa, it feels like great slash

02:08:33.260 terrible. But if you can get on like a woodway or a controlled situation like that, and you can just do

02:08:38.720 some like 70% for just getting through the motion kind of a tempo is what you, if you're a runner,

02:08:43.880 like you'd call it that type of stuff for very short distances, I'm talking like a 15 seconds,

02:08:49.460 just kind of stride it out. Okay. Slowly come back down. Wait a minute or two fully recover here.

02:08:56.120 Okay. Ready? Roll back into it. Two, three, four seconds. And then give me, pick it up for five

02:09:00.660 seconds, six seconds. Okay. Slowly back down. Just getting used to handling movement and being an

02:09:07.100 athlete and moving and not being, everything is locked into a position where it's structured and secure

02:09:12.620 and all that stuff. So I really, really like movement, athletic movement and multiple planes

02:09:18.300 for people. The last example I'll give you is just back to like high school, middle school sports.

02:09:24.440 We're going to play 10 minutes of basketball, go to the court. We're going to shoot, grab it up and

02:09:28.460 down. We're going to play racquetball as our warmup today. We're going to play badminton. You get over

02:09:32.460 there, I get over here, like two and two bad. You can do a lot of little different things that are

02:09:37.600 going to be multi-planar. It's going to be speed, agility, quickness at this point. So you're going to get

02:09:41.500 change of direction. All this stuff is the foundation piece you need to get to when we

02:09:45.680 actually do some speed and agility drills next year or wherever we're going to get to, which is

02:09:49.860 going to be part of your plan. So those are all a bunch of examples. I would recommend doing a

02:09:54.580 different one each day of those three. So it's Mondays, we're going to do med ball stuff. Cool.

02:09:59.440 Wednesdays, it's going to be pickleball. And then Fridays, we're going to do some jump stuff and some

02:10:05.440 medicine ball horizontal throws, whatever the case is, or it can be jump rope. It's going to be

02:10:09.580 hopscotch, things like that. I'm not against bounding broad jumps. I typically want to start

02:10:14.540 here two on two. So two leg leave, two leg land for this person. They don't have to be forward.

02:10:19.620 They can be lateral jumps. They can be combinations. They can be all kinds of things. Honestly,

02:10:24.380 you'd be surprised. Like I don't want to say this too loud in case somebody hears, but that stuff's

02:10:28.520 actually kind of fun. It's pretty fun. You're going to get a lot of giggles to be like, I haven't jumped

02:10:33.040 like this, like they're going to feel weird. And it's going to be way different than what they're

02:10:37.240 thinking the strength training thing is. You'll get some giggles. So that would be my intro to

02:10:42.840 every single bit. That's your opener. That's 10 to 15 minutes. Now we're hot. Now we're ready.

02:10:47.080 Now we're going to move into strength training. And so what I would still do is keep the same structure,

02:10:52.200 total body on all three days, because here's what's also going to happen. Once a month,

02:10:56.780 you're going to miss one of those days for more. A kid's going to get sick. I got too busy at work.

02:11:01.280 If you do body part splits, you'll start missing big things. You're going to miss chunks. So I like,

02:11:07.520 in these situations, these people, I want whole body every day. You're going to recover just fine.

02:11:11.860 I would do a different rep range. So I would do something like Monday is going to be say three

02:11:18.680 to four sets of five to seven reps. You're going to be able to go heavier. You're going to have a

02:11:24.380 minute and a half rest between each one. What RPE do you do there? Seven to eight.

02:11:29.320 Just for folks listening at the end of that, you're finishing with maybe two reps left in the

02:11:34.320 tank. Yep. Like for the working set for Wednesday, let's go 15 to 20 reps per set. So now you're

02:11:40.840 actually going to have less, you're probably going to drive less soreness because you're activating

02:11:45.340 probably less faster drivers. You're going to get more of a pump. You can actually like push the

02:11:51.480 repetitions and you can work harder and probably get a little bit less sore. And you'll feel more of an

02:11:55.780 acute satisfaction for a lot of people, right? Like you feel the feeling and your risk has gone

02:12:00.520 down a little bit. And then the third day you could go really wild and you could do something

02:12:05.400 like isometrics where you're just holding positions. Very good for joint, very good for

02:12:11.860 connective tissue and very good for just doing something different. All three of these are equally

02:12:16.020 effective for hypertrophy. So your gains and muscle size are going to be identical across the board.

02:12:20.500 And now you've introduced three different elements. Let's talk a little bit about isometric. I'm now

02:12:25.340 going to deviate from my patient into back to being Peter and interviewing. We didn't talk about it,

02:12:30.780 but everybody's probably heard of an isometric. It's force generation or muscle contraction without

02:12:36.140 movement. Big part of my recovery from shoulder surgery. I had a labral repair a while ago, and this

02:12:43.340 was the first thing I was permitted to do was begin humeral extension and flexion without movement.

02:12:50.300 And interestingly, I hadn't really spent much time doing isometrics outside of that with a few

02:12:55.500 exceptions. There were some dedicated, a lot of isometric deadlifts I was using as a precursor

02:13:00.580 to deadlifting, just a great way to warm up. But I don't think I was actually aware that isometric

02:13:06.080 training could generate or elicit the same hypertrophy response as isotonic or movement-based

02:13:11.340 contraction. Why is that the case? How does one know where to be in the range? So for example,

02:13:18.060 if I do a bicep curl, I can get every range of the bicep, but do I know if there's an isometric

02:13:25.680 benefit to being here versus here versus here? So are you 10% flexion, 30% flexion, 110% flexion?

02:13:34.240 I have so much to say on this one. Are we good for another two and a half, three? Are we going

02:13:38.580 another three hours? I will say this. We're clearly going to do a part two of this podcast.

02:13:43.460 There's a whole show on this area because of this. So you actually sort of invertedly asked,

02:13:48.240 well, what's actually driving muscle hypertrophy? It's not the workout per se, it's the stimuli.

02:13:54.180 So then what are those stimuli? That's a whole conversation. And the reason hypertrophy is

02:13:58.940 training-wise in terms of what reps to do, what type of exercise I consider to be the least

02:14:04.180 scientifically interesting is because it takes the least precision. Because the mechanisms are so

02:14:09.180 spread across different areas, you can go from A, B, or C. You don't have to have all three. You can

02:14:14.500 also have A and B, or you can have A and C, or you're going to get there. The muscle is very much

02:14:20.140 listening to that signal. It's not so much for other things. And so it's very easy to kind of land

02:14:26.860 accidentally in hypertrophy range, as long as a couple of things happen. As long as sufficient

02:14:33.060 overload occurs, you're going to get there. So this overload can happen over time. It doesn't

02:14:38.540 even matter how you achieve the overload. More volume, more reps per set, more weight,

02:14:44.200 extra range of motion. All these things are different strategies for progression. And if that

02:14:48.440 happens, you're going to be in a pretty good spot. Barring the mechanism discussion is we're just

02:14:53.160 going to get so far down the road here, we're never going to come back and answer your patient

02:14:56.440 question. But that's one thing to think about. So isometrics, the shorter answer is they're

02:15:01.880 going to be activating a number of those same mechanisms. So you're going to cause the same

02:15:06.620 amount of hypertrophy. Where do I be in that range of motion? Well, there's no answer there. This is

02:15:10.580 the primary downside of isometrics. This is where you'll mix it up, presumably.

02:15:14.400 Certainly mix it up. In general, muscles respond best to being at the highest stretch. So if you can

02:15:20.400 have that thing at the highest level of extension, generally, but it kind of depends on the muscle,

02:15:24.420 you're putting more. In fact, you can actually take a muscle fiber and hang it vertically and hang a

02:15:29.660 weight at the end of it, and it will grow. So being stretched that long is a very strong signal

02:15:35.220 to grow. And so when you generally train a muscle over a large range of motion, you're putting the

02:15:40.680 muscle on a larger stretch. And so that signal alone activates that whole anabolic cascade for

02:15:47.700 hypertrophy. So my default, if you're going to do an isometric, is to do it closer to the end range of

02:15:53.180 motion, where it feels the most tight, if you will, not the finished position. But it very much

02:15:57.940 depends on what you're after. Because the thing that gets tricky here is many muscles are single

02:16:04.140 joint. And so if you look at the soleus, as we talked about earlier, that crosses the ankle joint

02:16:08.140 only. But if you look at things like the gastroc, it crosses the knee and ankle joint. So putting the

02:16:14.060 soleus in the right position is only dependent upon the ankle. Putting the gastroc in the right

02:16:18.520 position is dependent upon the ankle and the knee. And so if the knee is flexed, you're never going

02:16:23.780 to get the gastroc to contract properly. You can't get a full contraction of the gastroc and a reflex

02:16:28.300 knee. You have to have an extended knee and extended ankle, because it's going to just get short on one

02:16:32.600 end of that spectrum. And the same thing happens with the biceps muscles.

02:16:36.560 So translation, a seated calf raise only works the soleus. A standing calf raise works both gastroc

02:16:43.840 and soleus. Correct. The same thing with like a tricep pushdown versus an overhead tricep

02:16:48.940 extension behind the neck. Now you're talking the triceps muscles across the shoulder joint

02:16:52.800 are now going to be put on stretch when you go behind the neck and bada bing, bada bing.

02:16:56.840 So that's why I recently saw a study that looked at tricep extension in flexed versus extended

02:17:03.060 humeral position. And the difference in muscle mass was significant when the arm was up, when the

02:17:09.720 humerus was flexed. Right. We see this in the hamstrings. We see this at the glutes. Muscles

02:17:15.240 like to be put on stretch. Well, they don't like it, but you're going to get... They respond to it.

02:17:20.460 You get the better compensation. Now that changes in a situation like what you were dealing with,

02:17:25.340 because example I use oftentimes, like imagine somebody who's kind of like a nagging elbow pain.

02:17:30.120 Like, man, like every time I do a lot of bicep curls and stuff, my elbow just gets me. Okay,

02:17:35.080 great. Hmm. Can we actually train the biceps without aggravating the elbow? Hard to do because

02:17:42.920 no matter which brachioradialis, biceps break, they're all going to cross the elbow joint.

02:17:47.160 What if that's a nagging shoulder problem? Aha. Well, now if we do like a preacher curl,

02:17:51.860 which is when your arm is out in front of you, you're shortening the biceps part that crossed the

02:17:56.040 shoulder joint and you can still work across the elbow joint and it will not aggravate your

02:17:59.860 shoulder. If you were to do the incline curl where your shoulder and arm is behind you,

02:18:04.440 you're putting it on stretch across the shoulder joint. Now those bicep curls are going to aggravate

02:18:07.560 your shoulder theoretically. So going back to isometric question, it depends on your specific

02:18:12.740 surgery and whoever you're obviously talented therapist or whoever was running that had you

02:18:18.180 on. I'm sure they were putting you in a position to get a little bit of activation in the joint that

02:18:23.280 they wanted, but not actually aggravate and let the thing recover. So the angle you pick

02:18:27.700 is dependent upon a number of factors. It could be sports specific. So if you take the case of like

02:18:33.060 a power lifter, you may just want to train in your final position of your squat and get very used to

02:18:39.140 being strong there. Going extra depth is only just going to make you worse as a lifter because you're

02:18:44.640 now traveling further distance and you've got to do more work. So there's no easy answer. That's one of

02:18:49.660 the reasons why we generally frown on isometrics is they just take a lot of intention where if I generally

02:18:55.020 just say do a normal full range squat, then you don't have to guess. But if you had an athlete

02:19:00.260 who said, look, even at this stage, I'm really willing to do a little bit of isometric, let's

02:19:04.820 say using the squat as an example, you're going to load the bar in a low position. They're going to

02:19:11.740 stand under a weight that is much heavier than they could ever lift and basically push up against

02:19:15.980 the bar. I mean, how are you doing an isometric squat, for example? There's a number of ways. So you can

02:19:19.980 do a bench, you can do a squat, you can do anything. So typically what we'll do is you'll put the barbell

02:19:23.520 in the rack. And so you can imagine like a squat rack. And you raise the arms of the rack. Yep.

02:19:27.880 And you have safety pins that run horizontal perpendicular to the ground. So instead of

02:19:31.520 putting the bar on top of those, you put the bar below them. And so you just lift up against the

02:19:36.840 rack and nothing moves. And so you can set your position, whether you're putting it behind your

02:19:40.920 neck for a squat, whether you're putting a bench below it and you just push up on those. We actually

02:19:45.460 have these built in the lab and on the bottom is a force plate. And those allows us to do an exercise

02:19:49.960 movement called. So that's how you can tell how heavy they're pushing. Right. And so we can measure

02:19:54.720 force produced into the ground at various positions. Does isometric offer any other

02:20:00.140 advantage over safety? Yeah, there's a ton of advantage to it. The advantage is you have less

02:20:06.840 degrees of freedom, less moving parts. So if I get you in a position, say in a squat, and your spine

02:20:13.120 looks good, and everything looks good, there's a very low likelihood you're going to get out of

02:20:17.040 position. The back squat is extraordinarily complicated. There's a lot of moving parts.

02:20:21.840 We have degrees of freedom at the ankle, knee, hip, low back, ribs, shoulder, neck. In an isometric,

02:20:28.600 nothing moves. All we have to deal with is compression. Sometimes compression is aggravating,

02:20:33.580 axial loading being specific, but axial loading is also fantastic for monumental density.

02:20:37.840 So the reason I threw isometrics in for our client kind of wrapping back to us,

02:20:41.720 you were talking about, you mentioned that as one of the problems. It's like, okay, great.

02:20:45.680 We know we can smash actually on these people with very low risk and get a lot of stimuli there and

02:20:50.860 not have to worry about getting in position at different parts. And we have this thing called

02:20:54.540 the strength curve, where when you do a typical isotonic movement, like a normal lift of a normal

02:21:00.020 dumbbell or something, you're only going to be challenged in the areas in the range of motion

02:21:04.920 where you're the weakest. So if you look at our study on lifting with bands, like heavy bands from

02:21:10.020 a deadlift, you're going to lift at the very, very bottom and you're going to have very low load. In

02:21:15.660 fact, you could have as much as a 40% reduction in load at the bottom, but when you come up and you

02:21:19.940 start crossing the knee joint and you start gaining mechanical advantage, it becomes extraordinarily

02:21:24.620 easy, but the bands start getting heavier. And so the actual tonicity that happens throughout the

02:21:29.620 entire thing is fairly equal, if not, well, certainly greater at the top. So you can train that whole

02:21:34.660 area of the strength curve with things like, this is why people use bands and chains and things like

02:21:39.680 that is to be able to produce more resistance in areas where they're stronger and they're not being

02:21:44.240 held back by the weakest position that they're in. To wrap that up, then you can actually then train

02:21:50.520 that. So then you can go into that weakest position and do an isometric in that weak position

02:21:54.820 without having to put a whole bunch of load on your body, like you would need to get in other spots.

02:22:01.440 Getting to and from it.

02:22:02.300 Right. So it's nice because with people like this, you could put her in like an RDL position,

02:22:07.060 like a hinge position, which is a kind of a complicated movement and just be like grab and

02:22:11.520 pull and nothing moves and they can pull as freely and as hard as they want. It's very difficult for

02:22:17.620 people with a low training age to truly express maximum force output on a free range motion because

02:22:23.560 there's too many variables. And when they're in position, is my back safe? Am I losing my balance?

02:22:29.000 If I just say, grab this bar, pull on this bar as hard as you possibly can, and nothing's going to

02:22:33.420 move. People can just go nuts.

02:22:36.020 So walk me through how you do that for an RDL. For example, you're going to do kettlebell,

02:22:40.120 dumbbell, barbell, RDL.

02:22:41.940 Barbell.

02:22:42.460 Okay.

02:22:42.880 Set the barbell in the squat rack, put it underneath and set the height of those safety pins to whatever

02:22:50.140 height feels comfortable for you. And so you'll then get in there and do that RDL and you'll pull up

02:22:55.060 against that bar and nothing will move and your back will feel comfortable wherever that range of

02:23:00.060 motion is for you. Your glutes can be there. Your feet can be in the right position. We get total

02:23:04.300 foot, big toe activation, get that whole arc.

02:23:06.700 You're doing this two foot down.

02:23:08.300 You do one leg. You would most likely start this thing two footed just to develop for this person.

02:23:14.080 In this goal, we're trying to let them express peak force output and feeling comfortable.

02:23:19.180 And how long do they need to stay in that isometric position?

02:23:21.700 Three seconds to some of the times we, with our athletes, we'll go up to five minute

02:23:26.260 isometric holds.

02:23:27.580 Up to what?

02:23:28.820 Five minutes. You can do like, we'll do a rear foot elevated split squat hold,

02:23:33.000 isometric hold for up to five minutes, which presents a tremendous neurological challenge.

02:23:38.000 I'm generally up for things that are ridiculous. I don't know that I could do it. Isometric hold

02:23:43.000 for five minutes.

02:23:44.280 You've ever done like super high volume lunges or split squats, like hundreds, things like that.

02:23:48.820 Yeah. I did a four minute set of split squats the other day.

02:23:51.800 Yeah. Okay. So just get into that position where your foot elevated just a little bit,

02:23:55.640 just hold it for two minutes to see. It's a fun task. You'll enjoy it.

02:23:59.180 No, I'm sure I will. Where are you creating the resistance for them? You're just, again,

02:24:02.660 same thing, bar over shoulder.

02:24:04.640 In that particular scenario, you don't need any. Time will be your resistance.

02:24:07.360 Oh, in other words, it's isometric only in that you're just holding a position.

02:24:10.880 Correct. It's like doing a wall squat. It's like a better version of a wall squat, if you will.

02:24:14.080 So you can go for a long time to kind of come back to your patient here. That's where we'd have those

02:24:18.540 three separate days. Yeah. This is interesting because I never, so I can really see now how

02:24:23.220 you could create a full day of isometrics. If you want it to go down that rabbit hole,

02:24:27.300 it's easy that one of those days is purely isometric.

02:24:30.500 In this situation too, even holding, you could hold a plank. That is an isometric exercise,

02:24:35.060 right? It's the one that people love holding a hip extension position and just making sure you can

02:24:40.940 actually continue to have your glutes on and utilize. You mentioned a squat earlier. So you

02:24:46.460 can do this in a couple of ways. You can actually go all the way down and truly hold that bottom

02:24:50.240 position. That is challenging though, if people don't have the right positioning, if you do,

02:24:55.520 it's a great, or you can close. It's a great way to build it. So I wouldn't be opposed to that if

02:25:00.080 they're close and doing 30 seconds, but here's the difference. I would cap that as failure,

02:25:04.900 not when they quit or get fatigued, but when they break position.

02:25:07.640 This is one of the tests we do with our patients and the excellent grade is two minutes

02:25:12.340 in a full 90 degree squat. Why do you stop at 90?

02:25:15.760 No, better than 90, lower than 90. So parallel, a thigh parallel squat, sorry.

02:25:20.080 Why thigh parallel?

02:25:20.960 That's just the standard we pick. But the failure, as you said, the goal is two minutes. Can you go two

02:25:25.920 minutes? And you fail not when you give up, you fail when you basically shoot your butt out,

02:25:32.080 lunge forward, make a compensatory movement that is beyond that. We use that as a great test of

02:25:38.480 strength without having to put people at risk. You could easily generate the day. You can also do,

02:25:43.660 so one of the things we haven't talked about yet is it's important that you're moving in multiple

02:25:47.080 planes. There's three major planes of movement, which is frontal, sagittal, and transverse,

02:25:52.220 which basically means you need to be moving like up and down, like a squat,

02:25:55.320 or you need to be moving things away to you and towards you like a bench press. And you also need

02:26:01.220 to be moving things laterally. So like a lateral lunge, as well as twisting and rotation. And so you

02:26:06.160 want to pick a few things in these areas. The other thing you want to keep in mind is single leg versus

02:26:11.760 either split stance or unilateral. And so there's no perfect number you have to hit here, but you would

02:26:16.820 want to select something across those three days where you're not doing everything is two foot

02:26:21.300 supported. So you mentioned one footed RDOs. You can do step-ups. You can do split squats.

02:26:27.000 You can do rear foot elevated split squats. There's a single leg press, single leg extension.

02:26:31.300 There's just a lot of ways you can do that. So you'd want to keep kind of an eye. I'm not going

02:26:35.680 like, all right, is everything I'm using barbell and everything I'm using to like, okay, maybe that's

02:26:40.260 not ideal. So maybe I'm going to use a kettlebell over here because I can actually do this movement

02:26:44.760 over here with a rotation or press. Okay, great. But now I'm going to pick dumbbell for this movement

02:26:48.680 and this movement over here, I'll use a machine. Lovely. Great. And now you're in a really nice

02:26:52.980 position where you're not getting held back so much by technical demands. This person is only

02:26:56.960 six months in a training. You don't want their whole day being learning how to do a movement.

02:27:01.420 And then boom, that 60 minutes goes up. But you also don't want to be like, well, these are too hard.

02:27:05.800 So let's just stay on machines the whole time. That's not a long-term investment. So we want to invest

02:27:09.740 a little bit in growth, 20%, 60% is in what you need to be here. 20% long-term development,

02:27:17.100 20 other percent is fun. That's how we generally think about that 60, 20, 20 split. So that's how

02:27:22.760 we split it. So the last piece here to wrap this thing up is I would finish every session

02:27:26.580 with something that either gets close to a max heart rate or is a personal pain point.

02:27:33.060 I always close off with katsu and there's some intense pain, but my last thing is always two

02:27:40.080 minutes of BFR on the air bike, which combines two beautiful personal pieces of pain.

02:27:46.460 What's the thing that they love to hate? What's the area that they want to grow? They hate their

02:27:50.440 triceps. Okay, great. Like we're going to finish the session with a tricep blast. We're just going

02:27:55.140 to smash it. They did some of the feel like, yep. Okay. I got the thing done. One thing people hate

02:27:59.740 is when they're not listened to. And when they come in, they're like, I want to get my glutes

02:28:03.640 need to get stronger or whatever. And you're just like, they're working them, but they're not real.

02:28:08.560 You want them to walk out. It's the double down concentrate on.

02:28:12.440 It's one little session or it could be whatever. We used to do this on Saturdays with the NFL players

02:28:17.340 because Saturdays were mostly a recovery regeneration day, which means they would never show up.

02:28:22.460 And so it was like, Hey, Saturdays are a gun show. We're doing nothing but biceps and triceps.

02:28:26.620 Be like, all right, who should update? You pick one, you pick one, you pick one,

02:28:30.200 you pick a tricep. Like everyone got to pick one. And we just do these ridiculous made up circuits.

02:28:34.800 And then they would all just get super pumped in their arms. And it was like, all right,

02:28:37.060 now go do your 45 minutes. Go see your PT, go see your athletic trainer. Like people are people,

02:28:42.060 give them a little bit of what they want and just make sure in one of those days we touch high heart

02:28:45.780 rate one way or the other. And when you touch high heart rate, a classic way that one might do,

02:28:51.260 this would be a Tabata type exercise where it's basically four minutes of intense work. What are

02:28:56.580 some ways that you might recommend getting high heart rate in there? Do you want to do it with

02:28:59.520 jumping? Do you want to do it on a bike, on a rowing machine? What do you like to use?

02:29:03.280 We typically want to keep away from eccentrics. This is where CrossFit is done very poorly. It's

02:29:09.020 like you're putting your, in a position of fatigue and very risky situations at a lot of times.

02:29:13.960 So something that's for this individual, again, I'm going to clarify that comment was regarding

02:29:18.300 this individual, probably not a great thing for other individuals. It's fantastic. You should

02:29:22.360 feel it. Air bikes are fine. Rowers are fine here. If you really want to, you can actually do specific

02:29:27.760 breath hold manipulation. So if you just alter breathing, so this is CO2 tolerance. CO2 can get

02:29:33.140 very, very high. You can deal with the suck without doing any physical work. This is all the stuff we've

02:29:39.140 done at XPT Live in the pool. You can do a lot of stuff with weights underwater and just changing

02:29:45.800 what you're doing with ventilation. And you can get to a level of pain very quickly that requires

02:29:49.860 very little physical trauma. There are lots of ways we can play that. Simple examples would be

02:29:54.900 do a 10 second sprint on the bike and then go into a breath hold. You want to see your heart rate

02:30:00.100 shoot up incredibly fast. And then you're going to come back out of that and you've got 30 seconds,

02:30:04.100 but you're going to go nasal only recovery breath. How long breath hold, by the way?

02:30:07.580 Well, you're going to see. The goal is maximum. Okay. In other words, go 10 seconds all out,

02:30:12.640 breath hold until failure, 30 second recovery nasal only. How many rounds of that?

02:30:17.960 Well, let's see if you can get three. One might be the answer though. You might go like,

02:30:23.000 I'm not even close and ready to do this again. Two might be there. You can also do that inhale

02:30:27.200 hold prior to the sprint. So you can do an inhale hold, breath in, hold, and then hit that sprint.

02:30:33.540 I mean, there's just a ton of ways you can get to playing with CO2 tolerance if that's part of the

02:30:38.080 equation. And again, you'll see your heart rate get up to damn near maximum. That doesn't require much

02:30:42.960 physical work. So if you need to spare joints, you need to spare soreness, you need to spare energy,

02:30:47.660 but you want to get that thing to the same. There's lots of tricks that way you can play.

02:30:51.840 So Andy and listeners, I think we have some really bad news and some really good news. The

02:30:57.100 really bad news is we've probably been talking for three hours and we've got one case study done.

02:31:01.980 Yeah, we've got one case study done and we haven't talked about a ton of physiology that I had in my

02:31:06.580 10 pages of notes here. What's really sad is I had 10 pages of single space notes that I wanted to

02:31:12.340 talk about. And we got into the first, I'm not being facetious. We got into the first half of

02:31:19.020 the first page, at which point I threw it over and totally rerouted everything we were going to

02:31:24.980 talk about based on your answer. And we have nine and a half pages of notes, plus a whole bunch of

02:31:30.800 questions that we didn't get to here. So the bad news is there's zero chance we're going to finish

02:31:35.420 this podcast now. The good news is I hope you will come back and we can do this again relatively soon

02:31:40.900 so that listeners can have a part two of this discussion, you know, hopefully within a month

02:31:46.580 or two months of part one. Is that something you're, I'm going to put you on the spot and ask

02:31:50.520 you this. You're willing to give us another episode here. I think we can, I'll talk to my people.

02:31:54.800 Your people will talk to my people and then we'll figure it out. Andy, this has been super

02:31:59.180 interesting. Literally we'll be putting a few of these things into practice tomorrow for me in the gym.

02:32:03.760 If I'm putting things into practice that are in just the purview of the guy who's never

02:32:08.000 exercised, I can't wait to get into more of my phenotype, which is, Hey, I do exercise,

02:32:12.820 but how do I take it to the next level? There's a lot of interesting things we can do when we get

02:32:17.200 to that fun conversation about everything from like, if you want to see behind the veil of

02:32:21.520 professional athletes, you want to see what they really do for sleep. You want to see what they

02:32:24.340 really do for nutrition. You want to see what they really do for training. We can go down that route

02:32:27.720 too. Well, Andy, this has been amazing. Thank you very much for your time, your expertise,

02:32:31.440 and I'll see you again in hopefully a month or two. Sounds good, man. Thank you.

02:32:35.720 Thank you for listening to this week's episode of The Drive. If you're interested in diving deeper

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The Peter Attia Drive - January 23, 2023

#239 ‒ The science of strength, muscle, and training for longevity ｜ Andy Galpin, Ph.D. (PART I)

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