The Peter Attia Drive - #151 - Alex Hutchinson, Ph.D.： Translating the science of endurance and extreme human performance

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

00:00:15.480 my website, and my weekly newsletter all focus on the goal of translating the science of longevity

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00:00:41.720 head over to peteratiyahmd.com forward slash subscribe. Now, without further delay,

00:00:47.740 here's today's episode. My guest this week is Alex Hutchinson. Alex is a science sports journalist

00:00:56.200 who writes about the science of running and other endurance sports. Before getting his master's

00:01:01.180 degree in journalism from Columbia University, he received his PhD in physics from the University

00:01:05.840 of Cambridge. He's a lifelong runner. And we start this podcast by talking about his incredible

00:01:11.520 passion for running, which he did competitively until about the age of 28. I first got familiar

00:01:17.420 with Alex's work reading a number of his articles, but became really obsessed when I read his book,

00:01:22.520 Endure. Early in 2019, I believe it came out the year before. It's a wonderful story about the

00:01:29.200 science of endurance and what the real limits are of human performance. And since that time,

00:01:34.340 I just knew I always wanted to have him on the podcast to talk about this with him.

00:01:37.860 In this episode, we talk about a number of things. We kind of talk about his background,

00:01:41.340 which is, you know, how does a guy go from having a PhD in physics to deciding he wants to go and do

00:01:45.360 journalism and then kind of go from doing sort of the beat journalism stuff to getting into science

00:01:50.800 and the science of endurance. And then we just talk a lot about stuff that people have asked me

00:01:55.800 so many questions about and we go into it in really tremendous detail, such as VO2 max and what does it

00:02:01.080 mean and how much of it is genetic and does it automatically imply superior performance? Even

00:02:07.500 some of the nuances of how it's measured, we talk about the difference between maximum aerobic capacity

00:02:13.180 and efficiency. And then we kind of transition into what these things mean for normal people.

00:02:17.400 So we obviously talk about the extreme examples of human performance. We talk a lot about breaking

00:02:22.560 the two hour marathon, which is something that was done recently in 2019, and then kind of bring it

00:02:28.380 back to what all of this means in terms of health. We get into the idea of challenging the idea that one

00:02:34.000 can exercise too much and challenging the J curve of mortality, discussing how maybe there are different

00:02:40.440 ways to think about this problem. We talk about high intensity interval training and a whole bunch of other

00:02:45.200 things that I think you'll find really interesting. So without further delay, please enjoy my

00:02:49.660 conversation with Alex Hutchinson. Alex, thanks so much for making time today to sit down and be part

00:03:01.120 of our inaugural video podcast here. I hope it's not a long run for a short slide. So far, it's been a

00:03:06.300 long run, but I have a feeling it's going to be a long slide too. Well, thanks for having me on, Peter.

00:03:10.680 I really appreciate it. And this is going to be fun.

00:03:14.140 So about two years ago, was it two years ago? Yeah, it would have been, it would have been like

00:03:18.660 February of 19. I read your book, Endure, which I literally couldn't put down. I think I read it in

00:03:25.780 two days. It was fantastic. And since that time, I've become such a huge fan. You're a very prolific

00:03:32.620 writer. I don't know how you do it. If you just search your name and go through all the magazine

00:03:36.380 articles you write, it's just a wonder you can do so much. There are so many things I want to talk

00:03:40.820 about today. But I want to kind of start with just a bit of your background because you don't have a

00:03:44.820 typical background, right? You have a PhD in physics. Yeah, yeah. Probably the least useful PhD in

00:03:49.540 physics anyone has ever attained. But yeah, no, I come from a different place in some ways, I would

00:03:54.820 say. You're a collegiate runner. And we actually have some friends in common because I think we're of

00:03:59.940 the same generation. Remind me, did you go to Waterloo? Did you go to Guelph? Where did you go to

00:04:03.960 college? I went to McGill for undergrad and then grad school in England. But yeah, we come from

00:04:08.360 the same part of the world. It's a small pool. So I think we've interacted with a few of the same

00:04:12.320 people. Yeah. And I think some of my friends probably ran cross country against you and ran

00:04:17.240 track and stuff like that. So for how long was track sort of your passion? I would say it was

00:04:22.480 the most important thing in my life until I was 28. Until that point, I would have put anything and

00:04:27.720 everything aside if it meant, I mean, I'm embarrassed to say it now, I made my brother reschedule his

00:04:32.080 wedding for a track meet. After 28, I kept training seriously until my early 30s. I still run six

00:04:37.880 days a week, train, race, all that. But 28, it was until then, it was the most important thing in my

00:04:42.900 life. And when did that start? What age were you? Was this like sixth grade? I mean, how serious were

00:04:49.180 you in grade school? I like to say I did win a race in senior kindergarten. I beat Stephen Mills,

00:04:53.920 nice kid, but a big kid. And I was like, wow, I beat the big kid. So I've always been the guy who

00:04:58.620 liked to run around. And I ran elementary school cross country, which involved showing up for a

00:05:03.120 race once a year. And I did well in that. I joined a track club when I was 15, the University of Toronto

00:05:08.000 Track Club, with the idea that I would train for three months because I was in a lucky position

00:05:14.000 because my birthday was after September 1st. So I could compete with the people a year younger than

00:05:18.160 myself. And I thought, well, let's leverage every edge I've got. I'll train hard for these three

00:05:23.640 months to see if I can stomp on these grade nines. And it worked. I ran well. And I kind of got hooked

00:05:28.920 and realized that I wasn't going to quit after three months. Where did you go to high school in

00:05:32.400 Toronto? I went to a school called University of Toronto Schools, which is a very, very small

00:05:37.160 school. It's academically focused. From an athletic perspective, the really nice thing is if you want

00:05:41.440 to be on a team, you're on the team. The qualifying process for school teams was going right through

00:05:45.760 the hallways and basically press gangs trying to get enough people for a team.

00:05:49.000 When you went to college, obviously McGill is a great academic school in Canada. They don't

00:05:54.320 have athletic scholarships. Was it a difficult decision to say, hey, I'm going to stay in Canada

00:05:59.260 for university or try to go to a US school where I could sort of parlay some of my running talents

00:06:04.520 to actually get some money for school? There's a couple of factors that played into that. One is

00:06:08.540 that I got mononucleosis in my last year of high school. I missed basically my entire final year of

00:06:13.540 high school. So I was a very, very good grade 11 runner. And then back then in Ontario,

00:06:18.980 there were 13 grades, but the high school I went to only went up to grade 12 basically.

00:06:23.960 So I graduated from high school without ever having competed as a senior in high school.

00:06:28.920 That's a long rambling way of saying I wasn't good enough to get a scholarship to any reasonable

00:06:32.440 place in the United States. So that discussion wasn't even really open to me. Whether I would

00:06:37.360 have, it's an alternative scenario that I would have been attracted by the idea for sure,

00:06:42.680 but that door wasn't open to me anyway.

00:06:45.060 When you showed up at McGill, what was sort of your specialty? Were you, I know you were a

00:06:48.760 miler. How competitive were you at the 800? How competitive were you at 5k and other distances

00:06:53.060 away from the mile?

00:06:54.220 I was a 1500 meter runner when I showed up. And with the assumption that I would be moving up to

00:06:59.420 5,000, you know, any minute now that I didn't, I didn't have a lot of sprint speed. I was a

00:07:03.700 strength oriented 1500 meter runner. As it turns out, the coach at McGill was an X 400 meter,

00:07:09.340 400, 800 guy. And his training was very sprint oriented. It was, it was long recoveries and all

00:07:16.680 out intervals. And so I actually ran better at 800 than I expected I would, but it was pretty clear

00:07:22.420 that 1500 was kind of the low end of my, of my sweet spot. I had so many friends who ran and many

00:07:29.240 of them said that the 800 was the most painful race there was. And I, I guess in swimming, that's

00:07:34.700 comparable to the 200. I think there's something to be said for that, that sub two minute all out

00:07:41.120 effort is really an unpleasant physiologic existence, which we're going to talk a lot

00:07:45.660 about that physiology. But would you agree with that? Having run so many distances?

00:07:50.280 A hundred percent, a hundred percent. The most painful race that I could run was the 800.

00:07:54.940 And, you know, I, and I also think about this in the context of workouts, specifically, you know,

00:08:00.500 at McGill talking about more sprint oriented workouts, longer rest, these sort of hard two minute

00:08:04.780 efforts. If I wanted an easy workout, the intuition would be like, you want to ask your coach for more

00:08:09.860 recovery or whatever. And I, it was the opposite for me. It's like, if, if the workouts seem too

00:08:14.640 hard, I'd be, can we cut the rest in half? Because then I know we're not going to be in that very high

00:08:19.240 lactate regime, which is, you know, a two minute all out effort is the single way to get the highest

00:08:25.020 possible lactate levels. And to me, that's synonymous with extreme suffering. I'd rather run a marathon

00:08:31.300 than an 800 in some ways. Yes. I found, um, when I used to tweak around with lactate levels,

00:08:37.060 I found that my personal best, best as though highest lactate was doing a 200 IM in swimming.

00:08:43.720 So two, 200, 200 individual medley, because it's upper and lower body with all four strokes,

00:08:48.900 it's that 200. So, you know, two minutes of unbearable pain, your personal best lactate

00:08:55.140 could be achieved with that. Personal worst call it. And yeah, I think that's something a lot of

00:08:59.080 people don't, there's an assumption that the longer equals harder. And it's like, man, no,

00:09:02.520 there's a whole different world of, of pain that you can get into in the, if you, if you're willing

00:09:07.620 to push yourself hard in those, those two minute efforts, two to 10 minute efforts, call it.

00:09:12.500 Now in your book, Endure, you talk about a very interesting, almost a throwaway meet. We would

00:09:18.620 call these dual meets and swimming, right? And it was sort of, again, I don't know if this was the

00:09:23.660 turning point for you, but it's sort of, as you read it, it comes across as a moment when you

00:09:28.760 first realize there's more to this than just the numbers. Like there's something going on in my head

00:09:35.080 that is changing the speed that I run in. Was that the, I mean, I want to hear the story. I want people

00:09:39.840 to hear the story, but was that a big aha moment for you? Or was that just the first of many steps

00:09:46.360 along a pathway? I'd say it was a huge aha moment for me at that time, but I'm not sure I understood

00:09:54.520 what the aha was. I knew that there's like, this is strange. And in hindsight, I realized that this

00:10:00.500 is what was that I'm sure we'll, we'll, we'll dig into this, but it was, you know, this, this started

00:10:05.800 my movement away from just like, we can calculate everything from physiology that, that endurance

00:10:11.960 is a little more complicated than the equations that you might start with.

00:10:16.480 Well, tell, tell the story because it's, I mean, again, you write about it so eloquently,

00:10:20.820 but it's, it's kind of hard to believe, especially as someone who I'm not a runner and I'm not,

00:10:26.740 you know, I'm not good at anything, but I still understand physiology quite well. And as the story

00:10:31.500 is unfolding, you're thinking there's a mistake. So yeah, walk us through that night.

00:10:36.660 As you said, totally meaningless meat, didn't have any big goals, but I was at that point,

00:10:41.820 this was third year university. And for about four years, almost three and a half years, I'd been running

00:10:47.300 between 401, 402, 403 for 1500 meters. 1500 meters is about 17 seconds shorter than a mile. So we're

00:10:56.280 talking like, it's kind of like the poor man's four minute mile. It's a significant barrier for

00:11:00.380 runners, but it's not at the level of a four minute mile. And so for me, it was like, that was

00:11:04.500 kind of a career goal. I wanted to break four minutes. If I could get into the threes, I felt like,

00:11:09.280 okay, I would have achieved something significant. But like I said, ever since high school, I'd been

00:11:14.800 running very close, couldn't quite do it. And at this meaningless meet, there was no competition

00:11:18.900 whatsoever. It was going to be, I was going to win the race no matter what. And it sort of at the last

00:11:23.420 minute, I just said, well, I might as well go hard and just see what I can do. And I'm unlikely to do

00:11:28.260 anything special in this context, but I'll go hard. And indoor track is 200 meters long. So you get

00:11:33.500 splits every about 30 seconds. And I came through the first lap and the timekeeper called out 27 seconds

00:11:39.780 for 200 meters, which is, it's about five seconds faster than four minute pace, which is an

00:11:45.400 eternity, an absolute eternity. 27 seconds is extremely fast. And it's a terrible way to start

00:11:51.640 a 1500 meters race if you're trying to run sub four minutes. And so I had, you know, conflicting

00:11:56.840 motions of like, oh God, you idiot with, oh, I actually feel surprisingly relaxed, but I need to dial it 0.99

00:12:02.460 back. Because presumably Alex, you'd run 27s in practice as splits and you know what 27 feels like. 0.99

00:12:10.120 And so on some level you're thinking, I feel really good because this doesn't feel as fast as 27,

00:12:14.140 right? Yeah. You're dialed into what 27 should feel like, but, and this is a, maybe an early clue.

00:12:19.940 You also know that nothing feels the same in a race, that there's some magic that happens in a race

00:12:24.920 and something that should have felt impossible will feel relaxed. And so you can kind of dismiss those

00:12:29.980 discrepancies and say, well, this is the magic of the race. We don't know where it comes from,

00:12:33.160 but it's the magic. And same thing in the second lap. I came through in 57 seconds, which is way

00:12:39.640 too fast, but I still felt relatively like good. And third lap 127. And so at that point, the two

00:12:50.080 things were happening. One is that I realized I was having a really good day. And two, I realized that

00:12:54.780 the splits were no longer meaningful to me because, you know, you memorize the splits for the races you

00:12:58.740 think you're going to run. At that point, I didn't know what 127 extrapolated to. And so the best

00:13:04.560 decision I maybe made in my racing life was like, stop listening to the splits. This is a special day

00:13:09.460 run to put your head down and go for it. So I, I did stop listening to the splits and I, I hammered home

00:13:16.020 and I ran three 52, which was nine seconds faster than my personal best at the time. And again, you really

00:13:22.200 have to emphasize that a one second personal best would have been a huge victory for me and nobody

00:13:28.880 PBs by nine seconds after they've been training hard for four years, five years. So it was just

00:13:35.620 absolutely mind boggling. And, you know, to cut to the chase, the postscript of the story is chatting

00:13:39.400 to one of my teammates afterwards who had taken my splits for me so that I could, as, as you do,

00:13:44.260 you put them in your training log and you plot them in Lotus one, two, three, and you analyze them

00:13:48.460 obsessively for months. So I wanted to get my splits and he's like, yeah, pretty good race.

00:13:52.940 And I was like, yeah, I can't believe I went out in 27 seconds. He's like, you didn't go out in 27

00:13:56.040 seconds. You were like 30 seconds. I was like, what? Second lap, 60 seconds. What? So at the time,

00:14:02.400 my theory was that this was a meet in Quebec in Sherbrooke. And so it was like, oh, the guy was

00:14:06.540 maybe translating from French to English and there was a three second lag. Maybe he just missed the start

00:14:10.960 with his watch. I don't know what happened, but he basically tricked me. He fooled me into,

00:14:15.160 into thinking I was having this amazing day. And then I did in itself. That was a very bizarre

00:14:21.940 circumstance. And then the question is what happens after that? Do I become a four minute

00:14:25.960 runner again, or can I run three 52 again? And the answer is neither. I ran three 49 in my list next

00:14:31.500 1500. And I ran three 44 in the race after that, which qualified me for the Olympic trials that summer.

00:14:37.260 So that's why I say you asked, was this an aha moment? And it's like, I knew right at the time,

00:14:41.600 it's like something has changed. It changed my career as an athlete, but then in hindsight,

00:14:47.500 I realized it also changed my understanding of, of what this whole endeavor was about and what we

00:14:51.660 were trying to optimize. I mean, again, I still sort of struggle with that. And of course you want to

00:14:56.120 extrapolate that. Does the same thing apply to strength sports? Well, presumably it does, right?

00:15:00.000 Could you easily trick somebody into thinking someone who thinks, oh, I could just never break 500

00:15:04.940 pounds for a deadlift and they're sort of forever stuck at 495 pounds. But is there anything really

00:15:10.560 preventing them from deadlifting 550 pounds, which would be as much of a breakthrough if they simply

00:15:15.700 believe that that's how much weight was on, if they simply believe that it was only 475 pounds on the

00:15:19.700 bar? I should add a postscript here is that the book came out, my old coach from high school, who I've,

00:15:24.880 you know, I continue to stay in touch with. He's a very big influence in my life. He read the book

00:15:29.080 and he's like, show me your training log. Like, which lots of people have said, right? Like,

00:15:34.200 come on, this wasn't all in your head. And I was like, okay, here's my training log. You remember it,

00:15:37.880 check it out. You tell me, was I ready to run 352? Because there wasn't a big discontinuity in

00:15:43.740 my training. It wasn't like that. I knew I was fitter. I knew I should be able to break four

00:15:46.760 minutes, but there wasn't like I suddenly was doing workouts way faster. And he looked through it

00:15:51.700 and his conclusion was, you know what, Alex, you were in shape to run mid 350s for sure.

00:15:56.540 You were not in shape to run. You were not doing workouts that predicted 344. So in a way,

00:16:00.780 the first breakthrough might've been in some ways, just catching up to the ways I was holding myself

00:16:05.900 back. I was overthinking things, stressing out all these things that people do in competitive

00:16:10.800 scenarios. I caught up to what I should be doing. And then that gave me so much confidence that I

00:16:15.080 kind of slingshotted right past where I should have been. And I was able to, you know, there's

00:16:18.980 always a conversion between what are you doing in workouts versus what can you do in races?

00:16:24.300 Everyone should be able to do more in a competitive scenario than they can do on a rainy Tuesday

00:16:29.020 night in Stoke or whatever. And I think the best conversions I ever had, the time when I was

00:16:34.720 competing, the farthest above my sort of baseline workout fitness was in the months after that

00:16:40.420 breakthrough. Cause I was just riding that high. And I believed that was, you know, semi-invincible.

00:16:45.240 So this is 96, right?

00:16:47.580 Yeah.

00:16:48.120 So you go to the Olympic trials for the 1500. How did you run there?

00:16:52.100 It's on YouTube. It's horrible. I came, I can't remember if it was a dead last or 11th in the

00:16:57.160 final. I made the final, which was okay. When I look back to it, I'm on the standing line next to

00:17:01.620 Graham Hood, who's the Canadian record holder at the time. So the camera lingers on Graham Hood.

00:17:06.980 So you can see me the whole time. And I just look, I think I might've written this book. I can't

00:17:10.620 remember, but it looks like I'm like waking up from a dream and looking around and, you know,

00:17:15.000 in my pajamas or something like that. I just, you know, I don't belong. I'm there. And you know,

00:17:18.720 I don't believe I belong there. A year later, I came back to the national championships. And by that

00:17:24.000 time I'd had a year to consolidate. No, I belong. I'm a guy who runs in the low three forties.

00:17:28.120 And that time I ran well, I ran, I ran, I came fourth. That was probably my, that was my best

00:17:33.500 finish at outdoor nationals and took a while for my confidence to fully catch up to me. I think

00:17:38.780 that was how that played out. And did you end up running the actual mile, the 1604 or whatever,

00:17:45.000 the non-metric mile? Cause you would have by that point broken the four minute mile, right?

00:17:49.480 You're poking your finger into a raw wound here. Oh God, I'm sorry. If you take my best 1500

00:17:55.140 and you plug it into the official conversions tables, it suggests that I would have run four

00:17:59.420 flat point zero one. I deprecate that entirely. I don't believe it at all. I'm confident that on

00:18:04.540 that day, I'll go to my grave saying I would have run three 59.9 that day. But in terms of miles,

00:18:09.320 you know, the thing is there aren't the miles just not very frequently run. I ran two competitive

00:18:13.200 miles in my career, one an indoor mile early season when I was in college. And then about four

00:18:19.680 years later, 97, I ran my best. I got a knee injury, was out 98, 99, 2000. 2001, I was trying

00:18:27.080 to come back and it was a slow process. And I ran a mile in Oregon at Hayward Field, which is the sort

00:18:34.160 of most famous place. It's a good place to go sub four, but I did not. I ran like 406. I just wasn't

00:18:38.900 back to my shape yet. And those are the only two miles I ran in my career. And I regret it. It's a

00:18:43.460 big thing. Like four minute miles, it's a very big thing. How many people have broken four

00:18:47.380 minutes for the mile roughly in history? It's a good question. I'm going to say,

00:18:52.080 I think it's a few thousand. It's fewer than more people have stood on top of Everest, I think is

00:18:56.800 the thing that people tend to say. I think that's still true. I think there's something like 800 or

00:19:01.580 900 Americans and globally, two to 4,000. I could be wrong, but that's my gut memory.

00:19:07.840 So by the time you're into the mid to late 90s, you're now a PhD student, I'm guessing.

00:19:13.560 Did you go straight into your PhD program?

00:19:15.140 I went straight there and I did a PhD in Britain where PhDs are, it's kind of a PhD light.

00:19:19.640 It's not as rigorous as a full North American PhD. It's hard in many ways, but it's different. So I

00:19:24.680 did a three-year PhD from 97 to 2000. What was the itch you were scratching there?

00:19:29.360 Were you a physics student in undergrad? Yeah. At McGill, you have to choose pretty

00:19:33.060 early. And so I did pretty much all physics in second, third, and fourth year. I enjoyed it,

00:19:38.360 but this was one of those things for me that I didn't know what I wanted to do. And one of the

00:19:42.040 pieces of advice I got coming out of high school is if you don't know what you want to do,

00:19:45.140 do the hardest thing possible. Because you can study physics and then become a journalist,

00:19:49.800 but you cannot study journalism and then become a physicist. There's a gradient.

00:19:53.720 You can only slide in one direction.

00:19:55.480 Yeah, exactly. So I have a brother who's five years older than me. And so he was finishing

00:19:59.640 university when I was finishing high school. And I had actually applied in, I think I applied to

00:20:03.800 McGill in history initially, but my brother had a friend who was finishing up in physics at McGill.

00:20:07.620 And she told him that in her class, there'd been like 60 men and five women starting the program and

00:20:14.340 they graduated four men and four women. And I thought, that sounds hard. I'm switching my major

00:20:19.580 to physics. So that's kind of how that started. And then coming out of undergrad, I really just didn't

00:20:25.160 know what I wanted to do. I applied to a bunch of things, again, in a variety of fields. But because

00:20:29.520 I'd studied physics in undergrad, the best opportunity I got was to go and do a PhD in physics. And I thought it

00:20:34.740 would be a reasonable way of allowing me to continue my running career. And it would be a

00:20:38.960 chance to go overseas and see a new culture and have fun. And I was certainly willing to give

00:20:44.520 physics a shot. I was considering physics as a career, but my decision was framed in a way that

00:20:49.940 even if I left physics, which I did end up in the end doing, I had zero regrets about spending three

00:20:56.380 years in England studying physics. How did your training change when you went to England versus

00:21:01.160 Canada? What were the biggest changes you experienced? Yeah, that's actually a really

00:21:04.840 interesting question because there's some huge culture changes. In terms of the actual, like,

00:21:08.000 how much do you run and stuff, not as big a deal. But you get to Cambridge and I show up for that

00:21:14.640 first meeting with the team and I meet the training secretary. And I'm like, what do you mean training

00:21:18.080 secretary? Well, he's the guy who's going to set our workouts. Like, what do you mean? What about

00:21:21.700 don't we have a coach? It's like, no. The athletic scene there is student run. So there's a kind

00:21:27.580 of a continuum in many things between the US at one extreme, Britain at the other extreme,

00:21:32.260 and Canada is often in the middle. And so sports in the US, collegiate sports are a big, big deal,

00:21:37.600 as you know. And collegiate sports are a medium deal in Canada, and they're not a big deal in the

00:21:41.860 UK. And so going there was an eye-opener in many ways. It's like, we're going to the national

00:21:46.640 championships, so we have to rent a van and then arrange a youth hostel where we can sleep the night

00:21:52.280 before the championships. That's not how collegiate sports work in the US. It's not even how they

00:21:57.220 work in Canada. But the flip side is, you have a lot of autonomy, and you take responsibility for

00:22:02.660 your training and your success. You're not a sort of acolyte or baby just being sort of fed what to

00:22:11.120 do from day to day. And so I don't have a systematic study to support this, but I think the

00:22:15.660 lifelong retention, the extent to which people develop lifelong habits and lifelong love of sport

00:22:20.840 and activity and competition, I think is much higher because you learn to be autonomous in university,

00:22:25.200 as opposed to the classic thing in the US is you're there for four years, you're representing

00:22:30.320 your college, and then college ends, and it's like, all right, I'm going to go work a job.

00:22:35.600 There's no encouragement to stay involved in sport, and you haven't developed the skills required to

00:22:41.080 self-motivate, self-organize, book that youth hostel or whatever the case may be. So that was

00:22:47.000 the biggest change, I'd say. So as you're wrapping up your PhD in physics, you have to make another

00:22:52.080 decision, right? Which is, am I going to go back to the US or Canada, do a postdoc, and then get on

00:22:55.920 presumably an academic track? Do I want to take this and move into industry where I can utilize

00:23:01.720 this? Because obviously at the time, there was probably no shortage of things that PhD in physics

00:23:05.480 could have been doing in Silicon Valley or Wall Street, right? Both would have been the heydays,

00:23:09.460 or do something altogether different. So how did you approach that decision?

00:23:13.280 I mean, you're right. This was, you know, making these decisions in 99 and early 2000,

00:23:17.200 and my PhD was in semiconductor physics. It was, you know, it was a good time to be in

00:23:21.020 semiconductor physics. And there was also, there's definitely the pull of both consulting and finance,

00:23:26.640 which is just the same way that it happens with Ivy League students in the States, in Britain. If

00:23:31.000 you're at Oxbridge, they're lining up to offer you vast sums of money. Like I said at the top,

00:23:36.340 running was the most important thing in my life until I was 28. So I considered some job offers,

00:23:41.820 but I wanted to focus on running. And I was very, very fortunate. I have parents who had a house,

00:23:47.380 they were willing to have me move back in and see what happens. So I spent, and at this point,

00:23:51.900 I was coming back from this three-year injury process. So I had been on a trajectory that I

00:23:56.960 thought was pointing favorably in 98. But then by 2000, when I was finished my PhD, early 2001,

00:24:03.540 I'd been out for a few years, and it wasn't clear. And I just wanted to give myself one year to see if I

00:24:07.340 could get back on that track of someone who might have a shot of making the Olympics.

00:24:10.700 So I moved back home. I did some tutoring of high school students, but basically I ran and I

00:24:17.060 went to the library and I checked out, they had a couple racks of world classics. So I basically

00:24:22.680 went through their entire rack of classic books, you know, 19th century literature, 20th century

00:24:27.620 literature, all the stuff that I didn't get to do as a physics student, you know, as an undergrad.

00:24:31.760 This is not a liberal arts program where I had time to pursue a bunch of things. It was all physics

00:24:35.740 and math. So I spent a year running. It was fun. I qualified for some national teams. I read a lot

00:24:42.420 of books and I did a lot of thinking about what I wanted to do. And after a year, I hadn't made the

00:24:47.520 progress running wise that could justify like, well, that could pay for an apartment, for example.

00:24:52.000 So I was like, yeah, okay, I'm 25 now it's, it's, or 24 or whatever it was. I need to do something

00:24:57.040 else. And I, so at that point I ended up applying for some postdocs and I ended up taking one

00:25:01.640 at the university of Maryland sponsored by the national security agency in quantum computing.

00:25:07.960 You know, again, it was sort of a hedge bets. It was like, I'll, I'll take this because the

00:25:12.180 research sounds really interesting and the people are fun and it may lead to a physics career,

00:25:15.660 but it sounds fun enough. And the one thing about academic life is if you're, if, if you choose,

00:25:22.320 you can make other things like running your priority. And so I went and I trained with a very,

00:25:27.500 very good training group led by a guy named Matt Centrowitz senior, whose, whose son went on to win

00:25:31.440 the Olympic gold medal in the 1500 in 2016. So I spent two and a half years there in physics,

00:25:37.680 kind of giving physics a shot, but also be as a way of, as much as I say running was the most

00:25:42.580 important thing in my life until I was 28, it was never the only thing in my life. And I also always

00:25:47.400 wanted to be continuing to develop in other ways and, and sort of making sure that my CV wasn't going

00:25:52.520 to be too empty at the inevitable point when I, when I had to move on. So, so yeah, so I took a postdoc

00:25:57.140 at that point and went back into physics. When you get to the end of that period of time,

00:26:03.500 presumably, is that when you pivoted to journalism as the next step? And if so, I mean, how in the

00:26:08.300 world did you gain the confidence to do that? Because we've established that the gradient

00:26:12.760 generally points in one direction and physics might be harder than journalism, but I don't

00:26:16.220 know that that's necessarily true at the individual level. Right. And it, yeah, it doesn't, it doesn't

00:26:20.620 impress anybody that you can solve the Navier Stokes equation if your job is to write an article.

00:26:24.500 So it's always hard to kind of write history in retrospect because you, you see the patterns

00:26:29.580 that you didn't see at the time. And so I'm never sure how, how accurately can I can explain

00:26:34.540 why I decided to do this, but there were a couple of things. I did have the starting of an interest

00:26:38.560 in journalism. I hadn't pursued it earlier. I wasn't like doing student newspapers in college or

00:26:42.960 anything, but I liked the idea of writing. And I'd actually, this is one thing that marks me as

00:26:47.700 unusual. I think as I, I had enjoyed writing up my PhD, everyone else was like, Oh, I love doing

00:26:51.760 the experiments, but I hate writing it up. I was like, man, those experiments were hard,

00:26:55.320 but it's kind of fun trying to explain why I was doing what I was doing, which is very hard to

00:26:59.760 explain. So I kind of thought I might like writing and I'd written a couple of, it's a stretch to call

00:27:05.380 them freelance pieces because they're basically like, I'd written a back of the magazine piece

00:27:09.320 for physics world. And I'd written a piece for athletics magazine, which is a track magazine in

00:27:14.080 Canada. And so I thought I'd like to give journalism a shot. So I applied for a bunch of

00:27:18.100 internships. And as you were saying, it doesn't work as clearly as you might think. I didn't get

00:27:22.800 any of these internships. And I thought, okay, this is my, my hopes of trying journalism are

00:27:28.220 stalling. Do I need to sit up late at night and write articles and prove that I can do it? And I

00:27:34.580 ended up kind of deciding that it was a credentialing issue, both a credentialing issue and an urgency

00:27:39.320 issue. I needed to jump into the deep end and force myself to survive as a journalist and also

00:27:44.720 have some way of showing people that I wasn't just a dilettante, even though I was at the time,

00:27:49.580 but I needed to show them that I was serious about journalism, that, that, that I had decided

00:27:52.920 to do it. And then I was going to learn the basic skills. So from, while I was doing my postdoc,

00:27:58.000 I applied to a few different journalism schools for, for master's programs. And that was helped

00:28:04.060 along by the fact that this was 2004 by this time. And I was timing it in such a way that it's like,

00:28:09.360 well, I'm going to give one last shot to make the Olympics. And if it doesn't, Olympic trials are

00:28:14.080 end of July, I'll start journalism school right after that. But what ended up happening is I got

00:28:18.500 a stress fracture in my lower back three months before the Olympic trials, which meant I was out

00:28:23.280 for 10 weeks. And then I did about two weeks of jogging and then went to the Olympic trials and

00:28:27.840 just sort of as a farewell to running. But that made it easier because I knew that at that point,

00:28:33.200 my Olympic dreams were over, were officially over. You know, some might say they were over before they

00:28:37.520 even started, but I'd been deciding that I didn't want to continue on with physics and I was

00:28:41.780 considering journalism. And then the end of running marked a natural transition for me,

00:28:46.980 or at least the end of that part of my, my track career, I wanted something else to be passionate

00:28:51.340 about, to be, to sort of pour that part of myself into. And I guess the one other story I'll relate

00:28:56.880 is that I actually remember at some point that year, we were working long hours in the lab, you

00:29:02.200 know, sometimes it was 12, 14 hours in the lab and I would leave to do my runs or whatever.

00:29:05.800 And I remember coming into the lab one morning, you know, after we'd been there late, we'd all

00:29:11.440 been there late the night before. And one of the guys asking me like, Oh, did you see that story in

00:29:15.820 physics today about, you know, whatever? I was like, no, no, I was in the lab for 16 hours, you know,

00:29:22.200 14 hours or whatever it was yesterday. I went home. I did not think about physics. I had zero interest

00:29:26.140 in reading about physics when I got home. And I kind of realized, Oh wait, that's what some of these

00:29:31.740 other guys do. They love it. It's their passion. And then that's great, but it's not mine. And so

00:29:36.260 I needed to find something or I wanted to find something that I wanted to keep doing where the

00:29:41.520 work and the play overlapped a little bit. You know, I thought about things like music that I care

00:29:45.560 about a lot and about running that I obviously care about a lot. And I thought, what is a possible

00:29:50.280 way that I can have a chance of maybe pursuing some of these interests of mine in a professional way?

00:29:58.080 And journalism seemed that that's what I think what pointed me to journalism is that

00:30:01.540 it wouldn't be easy, but there may be a chance that I could end up writing about running or travel

00:30:05.740 or music or something like that. Now, at this point, Alex, you've obviously got tons of athletic

00:30:11.740 experience as a runner. Your background in physics means there's nothing quantitatively you can't

00:30:17.120 understand. Had you at this point delved into the physiology of running or was that not yet

00:30:24.200 something you had really fully explored the depths of yet?

00:30:28.080 By the standards of what I would say now is like, no, I didn't have a clue. I knew nothing.

00:30:32.400 Now, I was the kind of guy who, when I got into running in high school, I got books about running.

00:30:37.760 And, you know, one of the first books I got was Tim Noakes' Lore of Running, which is 900 and

00:30:42.420 something pages. And the first 300 pages or so are physiology. I didn't really understand the

00:30:47.240 physiology when I went through it, but I was, you know, familiar with the terms. And there's some

00:30:51.180 other, I'm looking over at my shelf right now. I can, you know, I've still got my original 1990 copy of

00:30:57.300 Lore of Running right there. And there's a book called Better Training for Distance Runners,

00:31:00.820 which is co-written by a physiologist. So I had read all that stuff and I had this,

00:31:06.020 so I could talk about VO2 max and lactate threshold with other people who were interested

00:31:10.200 in this stuff. But I wouldn't say I had a deep understanding of where it came from.

00:31:13.700 I had a superficial acquaintance with the concepts.

00:31:16.480 So begins another apprenticeship, basically, which is now you're getting to learn physiology

00:31:21.540 as you start to write more and more about these topics.

00:31:25.480 This was not right away, I will say. I did one year of journalism school, and then I had 16 months

00:31:30.120 as an intern at a newspaper called the Ottawa Citizen, which had a great internship program at

00:31:34.900 the time. And I was covering car accidents and dog fashion shows and, you know, what have you.

00:31:39.600 I learned to write. I learned to write on deadline. I wrote, you know, 250 stories or something. You

00:31:44.480 mentioned being prolific. Like when you're the lowest man on the totem pole at a daily newspaper,

00:31:49.200 you learn to write fast, you know, multiple stories a day. And then my internship finished

00:31:54.240 and I became freelance, not because I had a bold vision, but because there were no jobs.

00:31:58.700 And, you know, initially, my first contact through a friend was with the bottom line, which you may,

00:32:04.360 your subscription may have lapsed, but it's Canada's accounting monthly. So I went to some

00:32:08.880 conferences on like forensic accounting and stuff like that. Because in a sense, I was running away

00:32:13.120 from physics and running was still a bit of a, you know, a tender spot. I sort of poured so much

00:32:18.700 into it. So I wasn't looking to necessarily immerse myself right away in these things. And it's only,

00:32:23.280 I would say it was about 2008. So a couple of years after I finished journalism school and after I

00:32:27.720 finished my newspaper internship that I started to get into writing about the science of running to sort

00:32:33.140 of bring those two interests together. Go back to that internship at the Ottawa Citizen. I want to

00:32:38.080 understand a little bit more about what you learned in journalism school as it pertained to teaching

00:32:43.500 you how to write. And then what you learned during that internship where you're on the ground,

00:32:49.460 right? It's the rubber meeting the road, so to speak. What were the two different skill sets there?

00:32:53.920 And how can somebody, I'm asking this for purely selfish reasons, by the way, how can somebody who's

00:32:58.340 constantly interested in improving their writing learn from that if they're neither able to go to

00:33:03.980 journalism school nor take a formal internship for a newspaper where they have an editor that's,

00:33:09.360 you know, giving them feedback constantly, presumably? What I got out of journalism school

00:33:14.820 was an understanding of the jargon for one thing, but also the forms. We tend to think of writing as a,

00:33:24.680 you think of what you want to say and then you write it down. In high school, a lot of us learned

00:33:28.520 the hamburger essay. There's five paragraphs, an introduction, then there's three main points,

00:33:34.840 and there's a conclusion. And in each, you have a topic sentence in each paragraph, yada, yada, yada.

00:33:40.260 So there's this really rigid structure. And what I don't think I realized until I went to journalism

00:33:47.180 school is that there are underlying forms for most of the articles we read. And a news story has a very

00:33:54.680 specific form. It's called the inverted pyramid. And a feature article, the kind of thing you read

00:34:00.800 in the New Yorker or something, it also has a certain form. Now, for good writers, that form is

00:34:06.580 invisible. And that form is also played with and your expectations are dashed. Sometimes you think

00:34:13.880 you know where the story is going, and then it goes somewhere else, and so on and so on. The point

00:34:18.180 isn't that you need to be slavishly following those forms, but you need to understand what the forms

00:34:23.660 are. So you can understand when you're deviating from them, you're doing it on purpose. And you

00:34:27.500 can understand what a reader's expectation is, even if the reader himself or herself doesn't

00:34:34.040 realize what that expectation is. And so there's things like, yeah, you need to have a billboard

00:34:41.360 paragraph that tells the reader what to expect. Anyway, I'll just sum up by saying that I learned

00:34:46.720 about form. Now, learning about form is not the same as mastering the form. And so you go to an

00:34:52.940 internship at a daily paper. And actually, good internships, hopefully, you're getting an editor

00:34:58.200 who's looking at your stuff, and you're getting a little feedback. But the reality is, it's a daily

00:35:01.420 beast. And there's not a lot of time for that. But you're writing, sometimes three stories in a day,

00:35:06.720 but certainly, typically, a story a day, you're rarely getting more than a day to write a story.

00:35:11.180 And you're getting a sense from editors and from other people of what's working and what's not. And you

00:35:15.440 can see what's working and what's not. And so there's the just doing it part of it. But I think

00:35:21.360 that would have been harder to benefit from if I didn't have a sense of what the structures are

00:35:26.820 that you're trying to transcend. You're trying to be more than just plugging in the pieces of a

00:35:32.940 jigsaw puzzle. But I mean, I give a talk on science writing a while ago to some postdocs

00:35:38.160 and grad students. And the main point I wanted to get to them is that every piece of writing has form,

00:35:42.500 whether it's a grant application or a scientific publication, or particularly, a lot of scientists

00:35:48.800 are interested in communicating their results to a wider public. And they have to understand

00:35:54.000 if they're writing for a newspaper op-ed page, what is the form? I guess the other thing I said

00:36:00.160 in that context is also understanding who the audience is. Those two things are interlinked.

00:36:04.920 If you understand who the audience is, you understand what their expectations are in terms of

00:36:08.300 what the piece is going to flow like. So anyway, what that boils down to is obviously doing lots of

00:36:13.800 it, but also trying to look at the writing that you like, the stuff that if you see a book or an

00:36:19.320 article that you like, or that explains things clearly, trying to break down like, so what are

00:36:23.780 they doing here? What makes this work? Did they have a particularly good introduction section or

00:36:29.160 whatever the case may be? So reading critically, I guess is what I'm saying.

00:36:33.000 I almost wonder if it's somewhat like athletes where you could have the same debate about good

00:36:36.340 writers being born versus made. In terms of scientific writers, I think Sid Mukherjee is incredible.

00:36:42.280 And I read his stuff and it's no different than watching a remarkable athlete do something and you

00:36:49.060 sort of think to yourself, there's probably no way ever that I could write like that, even if I

00:36:54.840 devoted every waking moment of my remaining life to this study, any more than I could swim or bike or

00:37:01.400 run as well as the most amazing athlete I see doing those things. Do you think that there's a parallel

00:37:06.600 there? I think there's a parallel and I would extend the parallel, which is that we can look at

00:37:12.080 Michael Phelps swimming and say, I will never be able to swim like that. But it's a mistake to

00:37:18.580 then say, swimming is all genetic and therefore I am doomed not to get better at swimming than I am

00:37:23.180 right now. And most people don't come anywhere close to fulfilling their quote unquote genetic

00:37:28.540 potential. So for sure, and I, you know, especially when I read fiction or when I read nonfiction by good

00:37:34.660 fiction writers who know how to write nonfiction, if it's not to get too confusing, the level of

00:37:39.580 language and imagery, to be honest, it's sometimes a little depressing to me because it's, I feel the

00:37:46.080 same as you. I'm like, yeah, there's no amount of workshops or practice that it will make me write

00:37:50.820 like that. And so I think another thing is just to, maybe this is too defeatist, but own who you are.

00:37:55.380 So I know that for me, I'm not a poetic writer, but what I hope to be is a very clear expository

00:38:02.800 and explanatory writer. So I will never paint the picture that I really admire in some other

00:38:08.560 writers writing, but hopefully I can excel at another aspect of it. Yeah, no, that's actually

00:38:14.620 a great way to compare the two. So with that, let's just start with sort of something you've

00:38:19.740 already alluded to. Let's explain what it is, talk about how much it matters, and then kind of get

00:38:24.840 into some examples. So let's start with a term that many people have heard before, but I don't

00:38:28.960 think most people understand what VO2 max really means. And eventually we're going to talk about

00:38:33.340 running efficiency and lactate threshold, and we're going to get into all of this stuff, but

00:38:36.300 let's make sure people understand what VO2 max is, both in an absolute term and then in a manner

00:38:42.200 that we normalize it by weight and what it is and what it isn't, how it's measured, how it matters,

00:38:48.340 and maybe we'll even talk about some notable exceptions. So VO2 max is the one physiological

00:38:54.360 parameter that anyone who's involved in endurance has heard of and has some sense of. The first

00:38:59.800 order analogy is it's kind of the size of your engine. Physiologically, VO2 max is telling you

00:39:06.000 how quickly you can take oxygen from the air into your lungs, get it into your blood, pump it to your

00:39:12.540 muscles, and then have your muscles use it in the metabolic processes that will provide energy to move

00:39:18.200 you to do whatever you want to do. So it's a rate. It's how much oxygen per unit time can you

00:39:24.700 process absolutely flat out. Now, the sort of backstory here is it was first sort of discussed

00:39:32.400 or measured in the 1920s by a guy named A.V. Hill, who was actually a very good runner.

00:39:36.860 The observation that he made is if you have someone, you ask someone to go out and run at a gentle pace,

00:39:42.760 they'll consume, let's say, two liters of oxygen per minute. Then you tell them to speed up. Now

00:39:48.200 they're doing three liters of oxygen per minute. Tell them to speed up again. And now they're going

00:39:52.860 pretty much, maybe not as fast as they can, but they're going fast. And they're using four liters

00:39:56.900 of oxygen per minute. And so you tell them to speed up again. And you measure it and they're like, oh,

00:40:01.480 they're only using four liters of oxygen a minute, just like last time. Speed up again. And they're still

00:40:06.260 just using four liters of oxygen a minute. There's a plateau. There's a point at which even though

00:40:10.180 you're working harder, you're not using any more oxygen. And so this plateau looks like it's a

00:40:15.920 physiological limitation. And it probably is in some sense. It's a controversial thing. But basically,

00:40:21.040 you've reached a point where no matter how hard you push yourself, you can't get more oxygen. And so

00:40:25.760 you can still go faster because you're starting to use other forms of energy. But this is the limits

00:40:31.540 of your aerobic system. This tells you what it tells you, we can get into. It's not clear what it

00:40:36.960 tells you. It tells you exactly what I just said. It tells you how much oxygen you can use. Does that

00:40:41.020 tell you exactly how fast you can run? No. There are a lot of other factors, but that tells you what

00:40:46.340 sort of aerobic engine you have to play with. I remember in high school, we would sort of talk

00:40:51.960 about, well, which athletes have the highest VO2 max? Is it the Norwegian cross-country skiers? Is it

00:40:57.160 the professional runners and cyclists and things like that? But people are usually used to hearing these

00:41:02.480 numbers reported, not in liters per minute, but in milliliters per minute per kilogram. So give an

00:41:10.520 example so people understand those differences. Because we usually talk about the outliers as a number

00:41:16.780 that's a bigger number than two liters or five liters. It would be, you know, sort of 75, 80 milliliters

00:41:22.840 per, just explain to people how those are different. Sure. So I'll use my own numbers. When I, you know,

00:41:27.640 typically when I was tested, I could get about a little bit more than five liters per minute. So

00:41:32.440 5.1, 5.2, if I remember correctly. Now, if you compared me to a rower, the rower would make me look

00:41:39.220 pathetic because the rower would be using seven liters a minute or more. But the rower is also 0.70

00:41:46.520 huge, twice my size or whatever. And so that doesn't necessarily mean that that rower is

00:41:52.800 better at using oxygen for me because the rower has way more muscle. And so the rower is

00:41:57.640 the amount of oxygen reaching any given muscle cell may be lower. So if you want to compare

00:42:03.940 apples to apples between athletes of different sizes, you divide, at least for a crude approximation,

00:42:10.560 you just divide by weight. And so the numbers we usually hear are rather than liters of oxygen per

00:42:16.320 minute, it's milliliters of oxygen per minute per kilogram of body weight. So for me, five liters

00:42:23.620 of oxygen per minute works out to something like 80 milliliters of oxygen per minute per kilogram of

00:42:32.240 body weight. There's a whole rabbit hole to go into is to say, well, why are we dividing by whole

00:42:37.900 body weight? Because, you know, there's a bunch of things like skeleton and organs and stuff that don't

00:42:42.740 scale. The adipose tissue doesn't matter. I mean, you could argue a better comparison would be total

00:42:47.900 liters per minute divided by lean mass divided by time or normalize the time. And then you're

00:42:53.920 at least getting the metabolically active tissue, presumably.

00:42:58.080 Yeah. And there's papers where they do things like, let's divide by weight to the power of 0.68

00:43:04.200 or 0.7, which is another way of getting it. Effectively, it's a way of approximating

00:43:08.520 just the lean mass, the metabolically active tissue. And you can go down that rabbit hole,

00:43:13.120 but I suspect you'll want to get to it. It's like at a certain point, it doesn't matter that much

00:43:17.360 anyway. So we don't need to, you can't just measure someone's VO2 max and know how fast

00:43:22.220 they're going to race. So it's, it's, it's useful, but it's not really, especially for comparing

00:43:26.980 between people. Now comparing within yourself, it tells you something if you've increased or if

00:43:32.460 your VO2 max has decreased, but in that sense, it doesn't matter what you're dividing by.

00:43:36.700 I remember there was a guy that I used to ride with, and this was not that long ago,

00:43:40.920 maybe five or six years ago when I was still, you know, somewhat competitive, at least with

00:43:45.480 myself. Actually, it's funny. My number was just like yours, except I was heavier. So I was about

00:43:49.880 5.1 to 5.2 liters, but I weighed more. So that worked out to about 70 mils per mig per kig was my

00:43:56.740 VO2 max. His was 55 to 60, but there was never a day that I could ride faster than him. Not one.

00:44:06.400 There's simply, and I always felt like, although we did the test so many times, I kept feeling

00:44:10.800 like the machine must've been broken on him. Like I knew my 70 was about right because I'd

00:44:16.580 been tested so much and that was lower than it had been when I was younger. So it seemed

00:44:20.760 appropriate, but I was always convinced that that there's no way he's only 55. The reality

00:44:25.960 of it is he may well have been, and he may have simply been a far more efficient athlete,

00:44:31.360 which we're going to get into before we get to the story of Oscar Svensson. Let's talk a little

00:44:37.300 bit about historically what people have believed the limits are of VO2 max.

00:44:42.000 We don't even have to go very far historically to get into a whole mudslide of confusion and debate

00:44:47.200 and disagreement. There's a lot of places along the way that could in some circumstances be the

00:44:53.220 bottleneck. Normally people tend to assume that what is it that causes VO2 max to plateau is essentially

00:44:59.420 what I think what we're talking about. And just one thing I should add here, it's like, why is that

00:45:03.360 interesting? It's because you think, well, if you want to measure endurance, just have someone run

00:45:08.140 a mile or whatever, as hard as they can. But any test like that depends on motivation, depends on

00:45:13.680 whether you pace it right. There's all these factors that come into it. The nice thing about VO2 max is

00:45:18.560 that in theory, it's independent of motivation. That's why scientists like it, because it doesn't

00:45:23.600 matter if the subject doesn't really care about the study. If you see a plateau, you know that's a

00:45:29.120 property of their body and not a product of whether they were excited about the study.

00:45:34.320 So the question is, this plateau, what is it that causes it? And it could be in the lungs,

00:45:40.920 it could be the heart, it could be the circulation, it could be the muscle's ability to extract it.

00:45:45.780 I don't want to pretend that I know the answer because it's still controversial. The picture that

00:45:49.240 emerges is that almost every part along this cascade is engineered more or less to what it needs

00:45:56.880 to be. And so if you perturb any of those elements, you can get limitations. So for example,

00:46:02.980 the conventional wisdom is that your lungs are not a limitation, you can always breathe enough in.

00:46:07.400 And so then the question is, can you diffuse enough oxygen from your lungs into your bloodstream and so

00:46:12.280 on and so forth. There are situations where and it's been for decades, it's been conventional wisdom

00:46:17.200 that the lungs don't respond to training because they're overbuilt. There was just a paper published

00:46:21.240 a big review in the last month or two arguing that, you know, in some cases the lungs aren't

00:46:26.660 overbuilt. And one of the situations is highly trained endurance athletes. They can be limited

00:46:31.320 by their ability to get enough oxygen in. And you can also run into situations where an athlete is so

00:46:38.320 fit, their heart is so strong, it pumps blood past your lungs so quickly that it doesn't have time to

00:46:43.700 fully stock up on oxygen. You get something called exercise-induced arterial hypoxemia.

00:46:47.500 So this is usually an issue at altitude, but in elite endurance athletes is actually about half

00:46:54.000 of them exhibited even at sea level. So they're already running into a limitation just in getting

00:46:58.640 oxygen from their lungs to their bloodstream. And then at every stage of the way, there can be

00:47:03.380 limitations if anything is knocked off kilter and certainly right down to the ability of the muscles

00:47:08.380 to first extract the oxygen from the bloodstream and then to make use of it metabolically in the

00:47:13.460 mitochondria. So there isn't one single answer, which is why you get these

00:47:17.260 debates because everyone is concerned. I have evidence that this is the limit. It's like,

00:47:20.540 yeah, but I have evidence that this is the limit and that's the limit and they're all the limit.

00:47:24.220 Yeah. I've always wanted to see the experiment where you took a group of athletes, maybe this

00:47:27.500 has been done. You run them all to max and then you reduce the FiO2 of the incoming oxygen. So

00:47:34.860 normally we do it with room air. So you're getting a fractional inhalation of oxygen is 21%.

00:47:39.780 And the way, of course, just for the listener, the way these things work is the way they're

00:47:43.580 calculating how much oxygen is being consumed as they're measuring the concentration of oxygen on

00:47:48.620 the way out. So you're calculating the delta. And so I've always thought, well, wouldn't it be

00:47:52.780 interesting to start selectively dropping FiO2, 21%, 20%, 19%, 18%. Now, presumably if the lungs aren't the

00:48:03.280 limitation, you should still see the same absolute delta. And you could at least start to eliminate

00:48:08.620 one of those variables, which would be FiO2 and capillary exchange. And then you start pointing

00:48:16.140 to some of these other variables. Again, I'm sure somebody has done this experiment, but I don't

00:48:20.680 know what it yielded. Probably not with the fine tooth comb that you're suggesting. People have

00:48:24.780 compared 21% to 10% or whatever, and 15%. I mean, it's interesting when you go to altitude

00:48:30.720 or the equivalent, when you reduce the amount of oxygen, funny things happen. The first thing you

00:48:36.060 would think would happen is like, you can't get enough oxygen, so you're going to go anaerobic

00:48:39.020 sooner, you're going to produce more lactate. And yet the opposite happens. There's something

00:48:42.700 called the lactate paradox. If you try and exercise to exhaustion at lower levels of altitude,

00:48:48.040 you actually give up when your lactate levels are lower than you would at sea level. And there's

00:48:52.560 debate about what causes this and even whether it's a real thing. But the picture that makes sense

00:48:57.220 to me is that these things are not just about how much oxygen is making it to the muscle. It's also

00:49:03.500 like, what is your brain oxygen level? And so you're getting these other circuit breakers

00:49:07.640 that are starting to come down that aren't even on this path from mouth to lungs to blood

00:49:12.520 to muscle. There's other factors that are saying, whoa, wait a second, oxygen is getting a little

00:49:17.120 low. So we're going to actually cut off the supply to the muscles or reduce it in order

00:49:21.120 to make sure that we don't get stupid. Prior to Oscar, because I want to talk about this 0.97

00:49:25.200 kid, his story is so interesting. And you wrote a great article about it. And I've read many

00:49:29.020 articles about him, including articles in physiologic journals. You'd had a couple sort

00:49:34.620 of freaks of nature out there in the nineties, right? So 90 plus milliliters per kilogram per

00:49:40.720 minute of VO2 max. What happens in sort of a garden variety day of December, 2012? Do you remember

00:49:48.360 when he shows up to a training lab? How old is he? He's like 17 or something?

00:49:53.020 17. I think he was. He was a former downhill skier who had taken like a talent screen to

00:50:00.980 see whether he'd be suitable for something like cycling. And I think he'd scored just

00:50:04.860 untrained, just off the downhill slopes. He was 74 or something like that. 74 milliliters

00:50:09.840 per kilogram per minute. So that he passed. And so he started training as a cyclist as a teenager

00:50:15.520 and pretty quickly scored 83, then 85, then 92. The initial reports were that he scored

00:50:22.800 97.5. But I think when the scientific journal came out, they said it was 96.7.

00:50:28.180 Which either way was still higher than had ever been recorded in human history.

00:50:32.300 And, you know, one thing we should say is there are reports of good people in their nineties,

00:50:37.500 but reports, high VO2 max numbers, they sprout very easily because it's hard to do these tests,

00:50:44.740 right? And in fact, a lot of the tests that people, the garden variety machinery used to do these

00:50:49.400 tests is not designed to handle seven liters of oxygen per minute. And so you get spurious results

00:50:56.520 and you get... So the previous king was a guy named Bjorn Daly, the greatest cross-country skier in

00:51:01.620 history, who in the late nineties reputedly tested 96, 96.0 or 96.6, depending on who you ask.

00:51:08.780 This was never published in a journal. This was basically the Norwegian ski team leaked it to the

00:51:14.980 press as a kind of PR move. And I asked a guy who was working in Norway at the time,

00:51:22.680 and he said they didn't believe the machine. He didn't believe the machine was correctly

00:51:27.060 calibrated, but he figured they decided that it was a good PR move anyway. So when we're talking

00:51:33.220 about high numbers and there's, you know, Matt Carpenter, 92, Killian Jornay, there's a lot of

00:51:38.440 people who have high numbers. Virtually none of them are published in the scientific literature.

00:51:43.920 The highest values, you know, you go back to the seventies where some of the great runners were

00:51:49.460 tested and you get, you know, Steve Prefontaine was 84 and there aren't a lot of published values

00:51:54.220 above the high eighties. So 96.7 is like, it's higher than the rumors, but it's way higher than

00:52:01.080 the verified numbers. So the first thing they did the next day is they disassembled the machine,

00:52:05.340 the metabolic cart, and send it back to the manufacturer to get it calibrated to find out

00:52:09.340 if they, you know, are we nuts? Is this real? Is this true? And it came back that, yeah,

00:52:15.440 it's working. And all the other tests done that day. Yeah, exactly. All the other tests that were

00:52:19.720 done in that day were all within line. Yeah. So they figured this is real. And so they,

00:52:24.160 they eventually, I mean, this, the story is longer. After his retirement, they published the data and

00:52:30.880 shared it, which was pretty cool. Well, I think the other thing that was very compelling was he was

00:52:34.100 tested again several months later. He'd put on two and a half kilos. So his number came down into

00:52:40.740 the eighties, but his absolute level of maximal oxygen consumption had barely come down. He went

00:52:47.200 from something like 7.2 liters to 7.1 liters, but the number came down from, you know, call it whatever

00:52:54.240 it was, 96 and change to 89 and change, which was accounted for by the gain in weight, which again,

00:53:01.060 is effectively like repeating the test and getting the same result. I agree. To me, that's the,

00:53:05.640 actually the number one piece of data is that, that off season test a few months later, later in

00:53:08.900 that year, it's like, okay, well, if he's doing the same amount of oxygen, we understand that people

00:53:13.080 can put on weight and lose weight, but the absolute value of 7.2 or whatever is suggests that this was

00:53:18.880 a real number. And, you know, the other thing to say is at 17 or whatever it was after he clocked that

00:53:24.700 96, a couple of weeks later, he goes to the world junior championships and wins the time trial

00:53:28.520 there. So on the surface, it's like, that goes to show if you have a big engine, you're going to be

00:53:32.480 a superstar. But of course the flip side of that, and where I, the reason I brought this up was to

00:53:36.460 say, why do most people listening to this who might even be able to recognize the best time trialists

00:53:41.960 in the world, the Bradley Wiggins of the world, you know, no longer active, but you know, the people

00:53:45.800 who go on to win grand tours and stuff, why don't we know this guy's name? Yeah. So he turned pro

00:53:49.780 when he turned 20, he was with an under 23 team called Joker. He was an okay cyclist. He did,

00:53:55.280 he had some good results. He had some bad results. I think it probably didn't help that he got a lot

00:53:59.980 of attention for this VO2 max value. So I think the expectations were probably out of line with,

00:54:04.000 with what was reasonable, both from his own expectations and other people's. And he ended

00:54:08.320 up retiring. I think he was 23, maybe like he took a break and then he officially announced his

00:54:11.780 retirement when he was around 23, went back to university and he's done, he's, he's gone.

00:54:17.220 So the aftermath was that there was a paper published, I don't know if, I think it was about a year ago

00:54:22.240 that sort of reanalyzed or responded to when they published his data and said, well, let's look at

00:54:26.580 not just his history of VO2 max values. Let's look at his efficiency at each point along the line.

00:54:32.480 So over the course of three or three years or whatever it was, where he had his multiple VO2

00:54:35.740 max tests. And you see this expected pattern. He starts at 74 and he goes 80 something, 80 something,

00:54:41.480 90 something, 96. And then he comes back down the ladder. You know, by the time he, after he retired

00:54:45.840 from cycling, he was back down to 77. So he's right back where he started. That's a simple story.

00:54:50.760 But if you look at the efficiency, you get a much more interesting story, which is that

00:54:54.900 he started out at his most efficient when he was untrained. And the more he trained,

00:54:59.000 the less efficient he got, meaning that he could deliver more oxygen to his muscles. He could

00:55:03.760 deliver more aerobic energy, but he, he used more aerobic energy in order to maintain a given pace.

00:55:10.180 Let's make sure folks understand how that's calculated. So now you look at a different graph

00:55:14.400 where on the X axis, you show wattage, which is the universal metric of output in cycling. And

00:55:20.640 on the Y axis, you show oxygen consumption. And so now you're looking at a graph that says for a

00:55:27.580 given output, how much oxygen, how much input do you need to get this output? And an athlete over

00:55:33.440 time should get better and better for a fixed wattage. You want to see what's called PVO2 come

00:55:39.960 down. So power at a given VO2 should actually come down as you get better in running. This would be

00:55:45.800 the VVO2. You want to get faster. So for a given oxygen consumption, you want velocity to go up just

00:55:52.740 as you would want power to go up. I might've said it backwards earlier, but I think you know what I'm

00:55:55.940 saying. So I got to be honest with you. I was actually very surprised by that. I wouldn't,

00:56:00.620 I would have been less surprised if it had been unchanged, but I was very surprised that it

00:56:04.680 deteriorated. Yeah. And there's, there's lots of debates about whether you can improve it,

00:56:09.440 but to actually see it get worse was, was so clearly. And so it's kind of monotonically,

00:56:13.600 there was an inverse relationship was definitely surprising. And it actually plays into a long

00:56:20.880 standing debate, which is the question of, is there an inverse relationship between VO2 max

00:56:25.960 and efficiency? So if you build your engine bigger, do you necessarily end up with a less efficient

00:56:30.860 engine? And this debate has been going on for a couple of decades now, and there's still no

00:56:35.540 consensus. And one, so one way of, if you just take a bunch of elite athletes and you measure their

00:56:41.200 economy, whether it's runners or cyclists, and you measure their VO2 max, you tend to see an

00:56:45.580 inverse relationship. The people who have the highest VO2 max tend to have slightly lower,

00:56:49.980 slightly worse economies. And the people who have the best economy tend to have slightly worse VO2 max.

00:56:56.460 There's a lot of possible explanations for this. One is that you don't tend to hit the lottery twice.

00:57:02.580 So if you happen to have a VO2 max, that's 92, then you're not that lucky, you're not going to have

00:57:09.780 the best possible economy. And if you're only looking at elite athletes, that means that everyone

00:57:14.640 else, there's going to have something special. So if they don't have the best VO2 max, by definition,

00:57:18.320 they have to have a great economy because they have to have something that's exceptional. And so you see

00:57:22.280 this inverse relationship that either you have good economy or you have good VO2 max.

00:57:27.500 And just to be clear, that's because we've selected for people whose dot product of those

00:57:31.480 two things is the best in the world. Yeah. If you're looking at elite athletes,

00:57:35.220 they have to have won at least one lottery, but they're unlikely to win two lotteries because

00:57:39.660 we're already looking at the 0.001%. So it's highly unlikely that you're going to have hit the

00:57:45.240 lottery twice. But so what the Oscar Svensson data points to is a different explanation, which is that

00:57:51.760 there's actually a trade-off that if you're optimizing one physiological parameter, it may come at the

00:57:56.720 cost of the other physiological parameter. That the training he did, which we can sort of surmise

00:58:03.280 must have been pretty good for increasing VO2 max because he got such a high one, may have actually

00:58:08.180 been bad for his economy. Not in the sense that his legs were wobbling or he had bad motion, but at a

00:58:14.920 metabolic level. And there was a paper published, again, in response to the Svensson case study,

00:58:20.320 reanalyzing his data and pointing to a potential cell-level explanation of what's happening

00:58:25.700 to certain enzymes at a given point. The biochemistry, frankly, is beyond me to fully

00:58:30.300 understand. But basically what they're saying is, if you're doing a lot of training that requires very

00:58:34.640 high, like VO2 max level outputs, your metabolism, your cells need to make choices to produce high

00:58:40.860 output instead of to be as efficient as possible. And over time, that's what you'll get better at,

00:58:45.220 and you'll lose that efficiency. And so you'll pay a slight penalty for optimizing your training for

00:58:49.880 VO2 max. Yeah. So that was kind of my take, which was not knowing more about his training was what

00:58:57.340 would happen if you took that engine, if you took that, that genetic gift and instead of maximizing

00:59:04.020 on VO2 max and pushing him from, I mean, a guy that gets out of bed in the morning or falls off a log at

00:59:09.440 74 is a freak of nature, but instead of pushing him to 96, you train him and he'd, he'd get up to 85 or 90

00:59:18.320 maybe, but you put much more effort into sort of zone two where you're right at lactative two. So you

00:59:26.660 push him. And by the way, for him, that would be like, if you looked, I remember looking in the paper

00:59:31.760 and applied physiology. I mean, you know, he's spending a lot of time in the three to 400 watt range,

00:59:38.160 but he could have probably been in the sort of 300 to about the 300 watt range where he's still

00:59:44.640 just under two millimole of lactate, but he's dramatically increasing mitochondrial efficiency.

00:59:51.280 And if that represented two thirds of his volume, yes, he'd have a lower VO2 max, but he might've

00:59:56.860 been a better cyclist. Certainly putting on the hindsight spectacles, I a hundred percent agree.

01:00:01.080 Whatever he did, he paid too high a price for that VO2 max. Just by definition, it didn't work out.

01:00:07.200 And again, we don't know exactly what his training was, but that makes a lot of sense to me. And I

01:00:11.240 think, and I think it sort of agrees, and you've talked a lot about this, but with the sort of

01:00:17.140 prevailing wisdom among endurance athletes is that, yeah, you know, 80% of your training should be

01:00:21.120 easy conversational pace. And what means you use to figure out what pace that is may vary, but

01:00:28.040 he needed to be doing something that was going to at worst not penalize his efficiency as much as he did.

01:00:33.800 I just remember even as an adult, like whenever I wanted to go and have a VO2 max test, just for ego,

01:00:39.840 you wanted it to be as high as it could. Like I would alter my training for four weeks and lose a

01:00:44.640 couple kilos. Like it's lose two kilos and start doing four to six minute all out intervals. That was

01:00:49.760 the recipe for raising VO2 max. So abandon all low end and it's four minutes all out, six minutes

01:00:57.600 mild, but those are killing workouts. Those really crush you. So yeah, there was just like kind of

01:01:03.740 a formula to make it happen. So let's pivot now and talk about something you've also written about

01:01:08.220 that I find completely amazing from a physiologic standpoint, which is the sub two attempt and the

01:01:14.680 incredible effort of Kipchoge. So I don't even know where to begin this story, but again, let's just

01:01:20.540 assume for a moment that listeners aren't familiar with who Kipchoge is, aren't even familiar with

01:01:25.520 the difference between an official marathon versus a contrived Nike marathon. Start from the beginning.

01:01:32.020 Okay. So the very beginning, I'll give you the medium long version of the story. The very

01:01:38.100 beginning is that in 2014, I wrote an article for Runner's World. It was about 10 pages long. I spent

01:01:42.480 months on it, analyzing the prospects for a sub two hour marathon and talking to a bunch of experts,

01:01:49.300 crunching data, blah, blah, blah. What would it take? And at the end of that article, my prediction was

01:01:53.760 that it would be physiologically possible to run a sub two hour marathon and that it would happen

01:01:58.740 sometime around 2075. So that, that was my context and I'll take ownership of the prediction, but

01:02:05.160 that's the general sense was that, yeah, it's possible, but it's not going to happen for a long

01:02:09.000 time. And just to be clear, Alex, what was the world record at the time? And did your prediction

01:02:13.800 speak to an official marathon or any form of marathon? Yeah. Yeah. So I was thinking about

01:02:20.900 marathons as they are currently run. Although in my article, what I said is, look, if it's going to

01:02:26.480 happen, it's going to happen on an optimized course. You're not just going to go to any old

01:02:30.660 course. So you're going to choose a course that optimizes temperature. It optimizes terrain. It

01:02:37.360 optimizes curvature. So there's a lot of things you knew right away, the way marathons were run

01:02:43.200 and mostly continue to be run. There's fat on the bone in a way that there isn't in sports like track

01:02:48.820 or, uh, if you look at the tour de France, there's fat on the bone, but no one cares about the time

01:02:53.200 compared to track cycling where everything is optimized. So marathons are this kind of anomaly

01:02:57.940 where they're run in a tour de France style in a very uncontrolled environment with, which differs

01:03:03.120 from, from race to race. And yet we care about time. And I think that's maybe an anachronism that's

01:03:08.860 going to fade away a little bit as we realize that, you know, you can, you can run a lot faster

01:03:12.380 if you optimize the course. But anyway, to answer your question, the world record was 202.57 by a guy

01:03:17.460 named Dennis Kimeto. So we're talking three minutes away from a sub two. If you say, how long did it

01:03:22.620 take us to come down three minutes? Well, in the mid eighties, I think it was 1986. The world record

01:03:29.220 was 206.50 by a millennia d'insimo. So we're talking a timescale 86, you know, call it 30 years to go four

01:03:38.240 minutes. Yeah, exactly. And of course the things are getting optimized as we go. So the current, you expect

01:03:43.440 the curve to be leveling out. There's less and less low hanging fruit to get. So in 2016, I got an

01:03:49.020 assignment from Runner's World to go report on this top secret Nike project. It was something they

01:03:53.660 called Breaking Two. It's a race they held in spring of 2017. And their mission was basically, they'd

01:03:59.740 spend about two or three years, 20 people full-time working on it, trying to engineer a sub two hour

01:04:07.080 marathon. And so they had started with a huge talent search. They sponsor a large fraction of the

01:04:12.860 world's best runners. So they brought 20 something of their best runners to labs to measure their

01:04:18.060 VO2 max and their economy and various other things and pick three runners. And then they went around

01:04:24.000 the world testing possible courses. They ended up settling on a Formula One racetrack in Northern

01:04:28.740 Italy. It was Monza, you know? It was, yeah. Which I think is where the highest speed ever reached

01:04:35.140 on a single lap is there. I'm obsessed with Formula One. So if you're interested, Monza is the fastest

01:04:42.300 Formula One circuit. You don't look at the maximum speed. You look at the fastest average speed. So

01:04:47.380 Monza has the fastest average speed of any Formula One circuit. There are other characteristics that

01:04:52.980 make Formula One circuits interesting, which have the highest G-forces, which have the highest

01:04:57.100 straightaway speeds, those things. But yeah, Monza has the fastest, highest average speed. And of course,

01:05:02.240 doesn't have much elevation change, which is probably even more important, right?

01:05:07.060 Yeah. So they used the junior loop, I think it was called, at Monza. So not the full one,

01:05:11.060 because that was the straightest possible with just the barely perceptible curves. I think it

01:05:14.980 was about a mile and a half loop or something like that. Also, it doesn't have much elevation

01:05:18.940 change. It's close to sea level, but it's not close to the sea, which makes the weather a little

01:05:23.380 more predictable. They optimized a lot of different things. You know, they're trying to optimize the

01:05:27.940 nutrition, the in-race nutrition, the aerodynamics. They're like doing things like sticking adhesive

01:05:33.420 bumps onto the legs of the runners to try and reduce the drag when they're swinging their legs

01:05:38.100 back and forth. Some of it's a little ridiculous. Some of it was significant. The two significant 0.84

01:05:43.620 things were they were going to have five or seven pacemakers basically blocking the wind for the

01:05:50.500 chosen runners for the whole way. Now, you can't hire someone to run a sub-two-hour marathon in order

01:05:55.840 to run a sub-two-hour marathon. So they had to have runners dropping out every couple laps and new

01:05:59.980 runners swapping in. That's not allowed according to the official rules of marathoning. So that's the

01:06:06.000 main reason that this race that Nike had planned was not and is not considered a world record

01:06:10.840 because it doesn't obey those rules. And then the other factor, the big factor is they introduced

01:06:16.300 a whole new type of shoe that had a curved carbon fiber plate embedded in the sole that improves

01:06:22.640 running economy. In other words, it allows you to burn less energy to sustain a given pace by about

01:06:27.840 4% on average. So put all these things together and all of a sudden it's like, we don't actually need

01:06:34.480 the runners to be that much faster than 202.57 if all these things we've come up with work.

01:06:39.820 We should be able to slice three minutes off the time with the shoes and the drafting and the course

01:06:43.940 and the weather and all these sorts of things. Of the three runners they ended up selecting,

01:06:48.380 Elliot Kipchoge was the reigning Olympic champion. And he was also probably the most consistent and the

01:06:54.440 best marathoner in the world at that time. He was, I think he had the second or third fastest time

01:06:58.300 in history at that point. And then they had a couple other guys who had good lab values. One of them

01:07:01.900 had the best running efficiency ever measured, but neither of those guys ended up being a factor.

01:07:06.460 Kipchoge ended up running two flat 25 at this Nike breaking two race. So two and a half minutes

01:07:11.740 faster than the world record. Didn't run sub two, but that was considered a victory because it was like,

01:07:17.720 nobody thought anyone would, even with all the sort of science and tech, nobody thought that it would

01:07:22.940 actually add up to a human running that fast. So then there was a sequel in 2019 funded by the

01:07:31.300 petrochemical company Ineos instead of Nike in Vienna, which basically replicated most of what

01:07:38.280 breaking two had done. They only brought Kipchoge in. They had a few different things. They had a

01:07:42.740 new pair of shoes, which is what became a very, very controversial. And this time Kipchoge ran 159.40.

01:07:49.900 So he ran a sub two marathon and it has galvanized and polarized the running world because

01:07:54.920 Kipchoge is the greatest marathoner in history, I would say, but these events left a bad taste in

01:08:02.260 the mouths of a lot of people, both for their, the sort of circus-like quality, but also because

01:08:07.120 of the shoes. The shoes became very controversial because it's not clear whether shoes that make

01:08:13.100 you 4% more efficient with a carbon fiber plate embedded in them are within the spirit of the sport

01:08:18.460 or within the rules of the sport. I mean, this sounds an awful lot like where swimming was

01:08:22.840 in 2008 and 2009, when the tech suits from basically 2000 to 2008 had gotten so quick that

01:08:30.920 by 2009, FINA said this world championships in 09 will be the last time there were technical suits

01:08:36.960 and away they went. And actually there are still some world records that stand nearly 12 years later

01:08:43.200 from those 2009. Yeah.

01:08:44.720 The surprising thing to me is that not all of them stand because at the time I remember

01:08:49.280 interviewing some swimmers and saying, so do you think you will never again set a personal best?

01:08:53.440 There was this sense that banning those suits would just completely change the record book,

01:08:58.000 but it has turned out that swimming has continued to advance. I guess there's advances in pool technology

01:09:02.540 and stuff like that. But yeah, it's exactly analogous debate. What role should the equipment play

01:09:06.760 in a sport that is not like Formula One, whose inherent attraction is its simplicity?

01:09:12.420 But to play devil's advocate, right? I mean, with the current running shoes you would wear,

01:09:17.560 if you were to go out and run a marathon, would they offer a 4% efficiency over leather you would

01:09:22.440 strap to your feet? It's a good question. I think they would raise my chance of getting to the finish

01:09:28.880 without injuring myself because cushioning is the big advance. The more sort of pointed analogy is

01:09:34.480 cinder tracks were common until the 60s. Then you have all weather tracks. I mean, it's apples to

01:09:40.240 pairs or whatever. Or look at cycling, right? I mean, consider a bicycle today versus a bicycle

01:09:45.760 20 years ago, not a hundred years ago. Just look. I mean, if you look at the bikes ridden in the late

01:09:52.860 nineties versus today, they're not even the same thing. They're not even close.

01:09:57.580 Well, the hour record is such a classic example of that because cycling did try and say,

01:10:01.240 you know what? Let's make it about the cyclists, not the cyclists. We're going to all ride

01:10:05.280 the 1972 Eddie Merckx special for the hour record. And the response to the cycling world was like,

01:10:10.920 okay, we're not interested in the hour record anymore. Forget about it. It's uninteresting to

01:10:14.640 us to go ride this stupid 1972 bike. And until they changed the rules again in whatever it was, 0.99

01:10:19.720 2015 or something. And all of a sudden, everyone's like, hey, all right, now we're interested again.

01:10:23.580 So the key that I would say in agreeing with you is that anyone who thinks that the progress of the

01:10:31.480 sport over the last 10 years, much less 50 years, much less a hundred years is all about,

01:10:38.360 well, we've learned more and we're digging deeper is kidding themselves. Technology is baked into the

01:10:43.160 improvement curve. Changes in circumstances, environment, and technology are baked into those

01:10:47.300 curves right from the get-go. Now you can acknowledge that and still say, I understand the

01:10:51.620 curve's going like this, but I don't want it to go to drop off a cliff. And the world records have

01:10:57.140 been absolutely knocked silly in the last two years since these shoes have become common.

01:11:02.400 I still think it's, you know, I think it was a tough call. I don't think it was obvious that

01:11:06.540 you could ban them until they'd already been used enough to realize that, oh, wait, this is real.

01:11:10.920 This is a big advantage, by which time it was kind of too late to ban them. Because the thing is,

01:11:15.420 I mean, as a guy who follows this stuff relatively closely, I'm used to press releases every year,

01:11:21.680 if not every day, that promise to upend the sport. And this is going to be the newest,

01:11:26.460 greatest, latest, best thing. So you ignore that stuff. And so even if Nike had said,

01:11:34.060 hey, by the way, just a heads up to world athletics, we've got these shoes and they're

01:11:37.820 crazy. Is it okay that we introduce them? And all the ingredients of the shoes are things that had

01:11:42.520 been used before. So there was nothing like, there was no like coiled spring in it. Carbon fiber plates

01:11:47.940 had been used before, including to set world records. So there was nothing, it's just Nike got the

01:11:52.240 recipe right. They got it so right that it changed the sport. And in the long run, things will settle

01:11:58.120 back into parody and we won't worry about it. But there was a period about 2016 to 2019 where it's

01:12:04.700 like, if you didn't have the right shoes, you probably weren't going to win the race. And that

01:12:07.720 is a little unfortunate. Where do you think this all fits into your prediction, whatever year that

01:12:13.720 was 2014. I mean, when do you think two hours will be broken on a legitimate road course with

01:12:21.240 full marathon rules that will constitute a world record? So that means it also has to be a marathon

01:12:25.880 that ends and starts in the same place. It can't be a one and done downhill like Boston or something

01:12:31.040 like that. Do you revise your estimate of whatever year you gave? Oh yeah, for sure. No, it's not going

01:12:36.560 to be 2075, which coincidentally was going to be my hundredth birthday. So maybe that was

01:12:39.620 subconsciously influencing me, but the answer depends on what you define as legit. So is there

01:12:46.080 something illegitimate about holding a marathon on a loop course? I don't see it. I mean, marathons,

01:12:51.520 it used to be, they were a big deal in like Madison Square Garden back in the late 1800s.

01:12:55.420 There's nothing inherent about saying you shouldn't run it in a circle. Yes, we love the big city marathon

01:13:00.520 experience and it brings the people together, yada, yada, yada. But if you're trying to break the

01:13:04.340 two hour marathon, the goal is not to be inclusive. So there's things like that.

01:13:09.360 Here's another thing they did. They said, we don't have a start time. We're not starting Saturday at

01:13:13.540 7am. We're starting sometime between Friday at 7am and Sunday at 7am or whatever. And we're going to

01:13:20.480 look at the weather forecast and we're going to make a call the day before, like 12 hours before,

01:13:23.660 so we can get the absolute optimal weather. Is that cheating or is that smart having a launch

01:13:29.660 window? So there's a lot of things like that. The key thing I think is two key things. One is

01:13:35.420 pacemaking. You can't have people jumping in halfway. That's the number one thing they have

01:13:39.720 to change for me to consider it like a legit sub two hour marathon. So you're going to have to

01:13:44.160 attract like the second best runners in the world to go and to have them work together so that, you

01:13:51.380 know, one group is leading through halfway and then the second group is going to lead to 30k or

01:13:57.160 something and then they're going to drop out and the chosen runners do it alone. So you're going to

01:14:00.500 have to optimize that to do that. You're going to need a ton of money and more generally, you're

01:14:05.140 going to need a ton of money to put on it. I would estimate Nike spent tens of millions of dollars on

01:14:08.720 its breaking to race. So my 2075 prediction did not bake any of that stuff into it. But now that

01:14:15.800 we've had a sub two and now that the official world record is two Oh one 39, if I'm remembering

01:14:21.180 correctly, we're within shouting distance of the two hour. I think some of those other factors may come

01:14:26.760 together that someone tries to put together a breaking to style race that still falls within

01:14:32.860 the bounds of legitimate. So I would say that could happen anytime in the next 10 years.

01:14:39.700 When's it going to happen? Just like it's a race where we showed up to Berlin or Boston or New York or 0.99

01:14:45.260 whatever, and someone happens to run sub two. I think that's still a long way away because again,

01:14:49.860 the progress has not been in humanity. The progress has been in understanding where the fat on the bone

01:14:54.860 is and cutting that away systematically. So if you take away all technology,

01:15:00.280 what is the difference between Roger Bannister and the fastest miler today? Again, get rid of

01:15:07.480 shoes, get rid of all of that. As a species, we have not evolved. So how much of that difference is 0.55

01:15:15.080 technology? How much of it is training, nutrition, everything else you'd bake into it? I mean, what would

01:15:21.040 be the buckets you would classify as the improvements? And what is the, I don't even know what the mile

01:15:25.620 record is today.

01:15:26.460 Mile record is 343. So it's come down 16 seconds. So for Bannister to today, the biggest bucket bar

01:15:33.680 none is training. Bannister is reputedly an underreporter. There was this sort of whiff of

01:15:39.840 amateurism where, you know, admitting you were training too hard was not done. But even if you

01:15:45.240 take with a grain of salt, his reports, you know, it was sort of half an hour a day, go out and do 10

01:15:50.040 by 400 meters. So we're talking like four or five miles a day, five, six days a week. Maybe he was doing

01:15:56.160 more than that sometimes, but he was training at a level, a very, very light level. And even one of his

01:16:03.000 contemporaries was Emil Zatopek, who was a Czech runner who-

01:16:07.580 Just a legend.

01:16:08.640 Yeah, absolutely. Like arguably the greatest distance runner ever.

01:16:11.960 Yeah, yeah, exactly.

01:16:13.120 He was starting to push the boundaries of how hard you could train. He was a guy who was going out and

01:16:17.260 doing 60 by 400 instead of 10 by 400. And so it's not like nobody understood that training worked,

01:16:23.060 but Bannister versus today, it's training is the difference. Cinder's maybe a second a lap,

01:16:28.680 like the track quality, the quality of the spikes, negligible and nutrition for a mile.

01:16:35.260 It's not just not that big a deal for a four minute race. If you fast forward to the sixties,

01:16:40.980 by the sixties, you've got people like Jim Ryan, who ran 351 for the mile as a teenager.

01:16:46.080 He's training like a beast. Most people could not handle, even modern milers would not dare to train 1.00

01:16:52.300 as hard as he trained.

01:16:53.120 What did he do?

01:16:54.900 So Roger Bannister was 10 by 400 meters. Emil Zatopek was 60 by 400 meters, but they were

01:16:59.420 mostly really slow. It was like another form of endurance. Jim Ryan was 40 by 400 meters,

01:17:04.520 but they were all hard. They were all close to as hard as Bannister was doing.

01:17:08.360 On what recovery?

01:17:09.640 I don't want to claim that I remember, but we're talking like one to two minutes,

01:17:12.700 probably, or a 400 meter jog and lots of intervals of, he was, it was a very interval based program,

01:17:19.620 but hard, really, really hard.

01:17:21.900 And what would he run those 400s in? Like how many of them would be sub 60 seconds? All of them?

01:17:27.080 No, not, not, not sub 60. He'd probably be doing those in like, you know, 66, 64. I, I, yeah,

01:17:33.740 I don't know that at the exact times, but it's at that volume in the context of high mileage,

01:17:38.980 he was doing them at a pace that was extremely challenging, not the sort of Zatopek style of 0.99

01:17:44.520 just kind of let's get tough and not, not worry about the pace. Zatopek's the guy who's like

01:17:49.040 in the laundry tub, just doing high knees in the laundry tub or holding his breath between

01:17:53.560 phone poles on his run. So he was all about just making stuff hard. Whereas Ryan was taking that

01:17:59.480 to a systematic level. We're going to train hard, but we're going to do it systematically with it,

01:18:02.820 with his coach, Bobby Timmons. I'd say you can't make much distinction between the training of the

01:18:08.020 1960s and the training of today. There were people who were training probably as hard in

01:18:13.300 the sixties. And if you take Jim Ryan's mile, three 51 cinders subtract four seconds, three 47,

01:18:20.440 the American records three 46 point eight or something like that. So by the sixties training

01:18:26.100 was mature and all the other stuff that we worry about all the nutritional aids and pneumatic compression

01:18:32.300 devices and ice baths and stuff. I'm not saying it doesn't help on an individual basis, but you

01:18:38.460 can't see it in the record curves or anything like that. Those things don't show up. Those don't leave

01:18:42.220 a mark in the big statistical picture. Do you ever follow horse racing at all? Do you ever follow

01:18:47.240 like the times that horses run and things like that? That's exactly the comparison I was thinking

01:18:52.340 of, which is that they've stagnated since the fifties, right? Well, I mean, Secretariat is hands down

01:18:58.160 the fastest horse that's ever run. And I read a very interesting argument on, oh, I don't know.

01:19:03.900 It was probably on Nate Silver's 365 a few years ago that actually made the point that we're getting

01:19:08.020 further from Secretariat now because we're actually seeing less diverse breeding of horses. So you're

01:19:14.540 just bringing less genes to the gene pool. And of course, Secretariat's genes were pretty unique,

01:19:18.420 right? It was an X-linked. So it was a sex-linked X chromosome gift that he had genetically. That's why

01:19:26.600 his male offspring didn't do anything special, but his female offsprings that would go on to pass 0.98

01:19:32.800 X chromosomes to males a generation later actually were somewhat special. But Secretariat's times were

01:19:40.280 unbelievable. I mean, when you think about it through the lens of even running, like to run a

01:19:45.400 mile and a quarter and to negative split by mile, all five miles, Secretariat's winning times at Belmont,

01:19:52.520 I don't think any horse will come close to that.

01:19:54.320 It's important to note that whatever amount of money we have in the running world that is

01:19:58.900 allowing us to optimize nutrition and training, and yet there's way more running and horse racing.

01:20:03.760 Like if there were physiological advantages that allowed us to run faster, they would be using

01:20:08.140 those on horses. So like the post-training massage or whatever, if that helped horses,

01:20:14.040 they'd be getting it or they probably are.

01:20:15.580 Yeah. So going back to kind of your experience, let's bring it back to this idea of what you're

01:20:22.820 now learning about endurance as you are back as a journalist now, and you're fully ready to go back

01:20:28.460 and visit your running routes. In the research for your book, what are you learning about your

01:20:34.600 experience on a rainy night in Quebec? And how are you able to put that in the context of what the

01:20:40.360 limits of endurance are?

01:20:42.020 So I guess the start would be, maybe to pick up the thread even a little earlier,

01:20:45.120 is I finally started to write about running, and I was doing it in a very conventional way,

01:20:50.360 the sort of what heart rate should you do your tempo run at and things like that.

01:20:54.880 What it meant is that I was starting to look at the literature and reading some papers. And I came

01:21:00.680 across a paper, and again, maybe 2007, 2008. It was a debate, and I think it was in the Journal of

01:21:07.680 Physiology. And the topic of the debate was, does dehydration impair endurance performance?

01:21:13.300 And I just remember being like, what is this like April Fool's? Of course, dehydration impairs

01:21:18.180 endurance performance. And it was a pro and con. And the con was Tim Noakes arguing, who's a very

01:21:25.140 notable contrarian scientist, let's say, from the University of Cape Town. And he was arguing that,

01:21:30.540 no, we have not shown that dehydration itself impairs performance. Thirst impairs performance if

01:21:35.500 you're thirsty. But if you drink enough that you're not thirsty, and even if you're dehydrated,

01:21:41.560 even if you've lost a bunch of weight, that doesn't impair performance. And he went through

01:21:45.560 all the literature, all the famous studies that show dehydration impairs performance going back

01:21:49.420 to the Second World War. And you look, and it's like, well, they were all thirsty. They were all

01:21:52.680 stuck in a sauna and not allowed to drink. So we don't... Anyway, all of which is to say,

01:21:57.460 all of a sudden, I was like, oh, wait, one of the things that I thought was beyond

01:22:01.360 debate is debatable. And so I started reading a little more and following this thread.

01:22:07.240 And I discovered that Tim Noakes had proposed this idea called the central governor model,

01:22:12.240 which was, in a nutshell, it's that when you run as hard as you can or exercise in other forms as

01:22:17.720 hard as you can, the reason you stop or the reason you slow down or the reason you aren't able to go

01:22:22.320 faster is not because your legs aren't capable of going faster. It's because your brain is protecting

01:22:26.660 you. It's sort of putting on the brakes before you push so hard that your heart runs out of

01:22:31.140 oxygen or whatever the case may be. And this was highly controversial. It was a fringe theory at

01:22:37.200 the time. But that's when I started to make the connection to my race in Quebec, my 1500 breakthrough

01:22:44.660 and the whole career of like, why do I have a good race one week and a bad race the next week,

01:22:49.240 even when physically there's nothing different? Why does it feel like sometimes I'm able to dig

01:22:54.080 deeper? If it's just multiply your VO2 max by your running economy, divide by your lactate

01:22:58.500 threshold or whatever, there shouldn't be any change. These things don't change from week to

01:23:03.300 week. And so that got me interested in the role of the brain. Now the central, I should, let me just

01:23:08.440 jump ahead and say the central governor model, people don't really talk about that anymore.

01:23:12.100 It was a model that emphasized the importance of the brain in understanding the limits of endurance,

01:23:17.180 which has then led to a whole bunch of further research, which is what captivated me.

01:23:22.180 Because it's like, nobody needed another article on VO2 max is oxygen or whatever. Although I

01:23:27.720 shouldn't say that because I've written a few articles about VO2 max. But what struck me as

01:23:31.320 interesting and what even by 2009, I was like, this should be a book about this that tries to

01:23:36.500 explain this to all the people like me who I know are interested in this stuff, but don't realize

01:23:42.560 that there's this debate going on in the literature about how do we bring the brain in, not just in a

01:23:48.720 sense of like, you have to really want it to try really hard, but to understand how the brain is

01:23:53.520 influencing or controlling or playing a part in determining the limits of endurance.

01:23:59.740 Where do you think this fits into health? I mean, this is clearly an important topic when we're

01:24:07.560 talking about sports, right? When we're talking about endurance sports, like running and cycling and

01:24:12.360 swimming, the purpose of the sport is to be fast, is to have endurance and speed at that right

01:24:17.300 combination. Many of the people listening to this podcast are no longer competing. You know, you're

01:24:22.460 still competing, but most people aren't. I don't compete at anything anymore. But I hate the term, but

01:24:28.600 quote unquote, cardio exercise or endurance-based exercise, we would still agree is still an important

01:24:34.840 pillar of health. So how do you think about that? And more importantly, how do you think about what

01:24:40.760 you've studied applying to health? And one of the things I want to talk about, because it's so

01:24:45.660 interesting, of course, is at some point, does exercise become counterproductive? And maybe even

01:24:50.900 what are the benefits specifically? For example, energetics, efficiency with metabolism and how that

01:24:57.360 can fight disease. So in any way you want to start that discussion, like how do you start to think about

01:25:02.000 it both scientifically and even personally? Yeah. So that's a big bite to chew on. You've mapped out the

01:25:06.560 next three hours of our conversation. But one thing I would say is, I mean, look, I don't want

01:25:11.260 to oversell it and say you must understand your absolute limits in order to be healthy. But if we

01:25:16.220 think about the barriers to exercise, the barriers to being physically active, I think for a lot of

01:25:20.160 people, if you interpret the distress signals you feel when you start exercising as signs that your

01:25:28.500 body is reaching its limit, that's a very distressing thing. If you're like, I'm going to start an

01:25:33.560 exercise program, I'm going to start brisk walking, I'm going to start running. And you feel you're

01:25:37.260 panting, you're out of breath, your legs are burning, you're like, I'm going to die. And you

01:25:40.940 stop. And so I think understanding, it's not so much about how to change your limits, but understanding

01:25:47.620 what those limits represent, understanding that they are not signs that you're going to die. This

01:25:52.360 is just information. I would say, and I haven't thought this through, maybe it's not true, but I would

01:25:57.060 say off the top of my head, any meaningful form of exercise that's going to do you substantial amounts

01:26:01.100 of good is going to involve dealing with discomfort in one form or another. And if you can get to a

01:26:06.520 place where you understand that the feelings of discomfort are not signs that something is going

01:26:10.460 wrong with your body, but they are just information, they are telling you where you are on the road to

01:26:16.040 reaching your limits. And you don't have to go to your limits, but you also don't have to stop.

01:26:20.080 You're allowed to just interpret that as information and say, okay, understood, I'm out of breath,

01:26:25.360 but I can keep going. To me, at least, that's a useful insight to take from this.

01:26:29.440 We can get deeper then into, you've raised some very interesting and controversial questions about

01:26:34.340 how much exercise is good. What kind of exercise do we need to do? I don't know where you want to

01:26:38.200 start with that. Because we don't have three hours, although I mean, when we meet in person and share

01:26:45.280 a meal, we certainly will take those three hours. But let's start with two opposing points of view with

01:26:51.120 respect to exercise. So one point of view says the exercise longevity curve is J-shaped.

01:26:57.120 So at the far end of the spectrum, no exercise is a really bad thing for mortality. As you increase

01:27:05.680 exercise, mortality improves, improves, improves, improves, improves, improves. And then it kind of

01:27:11.640 gets to your best all-cause mortality. And if you continue to increase exercising beyond a certain

01:27:17.260 volume, this is generally discussed in volume of exercise, you actually see a little uptick in

01:27:22.820 mortality, suggesting that once you go beyond a certain point, again, I want to stress this is

01:27:27.980 in volume of exercise, you don't get any more benefit and you may actually have more harm. And

01:27:33.140 a lot of times this is harm that comes in the form of cardiac dysrhythmia, could be even

01:27:38.160 atherosclerosis through endothelial damage, fibrosis, things like that. There's another body of literature

01:27:43.860 that says, no, it's more or less a monotonically improving curve. And again, we all agree that at

01:27:51.260 one end of the spectrum, having really poor cardiovascular fitness, again, we could measure

01:27:56.540 this in VO2 max or something like that. As that improves and you get fitter and fitter and fitter

01:28:01.880 and fitter, all-cause mortality goes lower and lower and lower. And there is no J to that curve.

01:28:07.120 How do you think about reconciling those? And I want to point out at the outset,

01:28:13.100 this is a discussion that only really impacts like 1% of the population because 99% of the

01:28:19.380 population are on the side of the curve where they could always benefit from exercising more.

01:28:23.780 But you, for example, might be one of those people who's in the 1% where, I don't know,

01:28:29.300 what's your weekly mileage right now? Fortunately, it's only probably about 20 miles. So even James

01:28:34.020 O'Keefe would give me a pass, I think. Yeah, yeah, yeah. So walk me through how you

01:28:37.660 think about that because I have to be honest with you. I've seen examples of those athletes who go

01:28:43.420 a little bit too far, who probably have a genetic susceptibility to dysrhythmia and then they go on

01:28:48.780 and get these dysrhythmias. But at the same time, they're few and far in between. So I'm still a bit

01:28:54.940 on the fence about this one. Again, just purely from an intellectual standpoint, I don't think it

01:28:58.220 applies to me anymore. It probably did at some point. It's a good question and it's an important one.

01:29:02.820 A few things I want to say. First, I'm a runner, right? So take what I say, understand where I'm

01:29:07.640 coming from. I'm also a human. I don't want to die. So I try to look at this data as dispassionately

01:29:12.640 as possible. But obviously, my knee-jerk reaction is like, let's find holes in this data that

01:29:17.500 suggests running is bad. So get that on the table. Second, there's no doubt that there is a reverse

01:29:23.660 J curve. If you try to run 28, 28 hours a day, it's not going to be good for you. Nothing is good for

01:29:30.140 you if you push it far enough. So the real question is, where does the uptick happen?

01:29:35.880 Third thing I want to say is the data on this showing that you do a little bit, you get some

01:29:40.300 benefits, and the more you do, it gets worse and worse. One really interesting thing that came out

01:29:45.140 of that, and there were a few studies about eight years ago that showed that, is that actually the

01:29:49.320 dose you need to get most of the health benefits is very small. And I do think that's an important

01:29:53.980 message. You do not need to train or for or run marathons in order to be optimally healthy,

01:29:59.240 at least to within the 90% or whatever. You're going to get most of what you get from a very

01:30:03.960 modest amount of exercise. And so that's a great message. Can you quantify that, by the way, in

01:30:08.640 terms of running? Let's put some numbers to that. If you're talking about a person who maybe was

01:30:15.580 active in high school and college, but they're 10 or 20 years out of that, they've been caught up in

01:30:20.560 the challenges of starting their career, starting their family, et cetera. They wake up, they're 40

01:30:25.900 years old and their waist is five inches bigger. They've got metabolic syndrome. They're not in

01:30:33.460 dire straits. It's not like they're going to die in the next 10 years, but they've got the message

01:30:37.360 which says, hey, the one thing that is really missing is your exercise. What would you say if they

01:30:44.240 came to you and said, Alex, just tell me the minimum effective dose. I don't want to run any weekend

01:30:48.940 races. I like running. I used to love it or rowing or whatever their activity is. How many hours or

01:30:54.880 how many miles do I need to do a week to just get 80% of the benefits with 20% of the efforts?

01:30:59.540 The Cooper Clinic study, which was like 50,000 people or so that came out four or five years ago,

01:31:05.260 their number was five to 10 minutes a day. I don't fully believe that, but that was their number.

01:31:12.860 So you're talking like an hour a week and that's just going out for a run. Personally, maybe

01:31:18.880 we can get into this. That's not my definition of an optimal exercise routine. I would include

01:31:23.880 some high intensity stuff and strength is another thing, but there's making some claims that would

01:31:28.460 have very, very low minimum effective dose. Personally, I would say I'm probably running

01:31:33.280 about 20 miles a week right now, which is six days a week, half an hour with a couple of hard days.

01:31:39.000 To me, that's on the low end of, I think I would be healthier if I did more at this point.

01:31:44.320 You do? You think you would actually be healthier? I know you'd be a better runner,

01:31:47.940 but would you be a healthier, would you live longer?

01:31:50.820 I think I would. The first thing I would do if I had instant motivation powder that I was going

01:31:55.120 to dust on myself, I would up my strength training routine. That would be the first thing I do

01:31:58.880 if longevity was my first priority. Oh, I'm sorry. I misunderstood. So you

01:32:03.680 wouldn't necessarily run more. You would take extra time and add it in the weight room or do something

01:32:08.840 else? No, I would run more. If I was prioritizing, I would prioritize strength first. But I think

01:32:13.740 because I come from a background where I'm already used to running, 20 miles a week doesn't stress me

01:32:19.060 very much. It just slows down my decline. I think I could benefit from, let's say, one longer run a

01:32:25.920 week or something like that. This is not supported by anything other than my gut. So the five to 10

01:32:30.540 minutes a day, it's definitely the right place to start if you're the 45-year-old sedentary getting

01:32:36.940 back into it. But I think you might want to push something a little higher than that.

01:32:41.400 Or certainly if you're doing 60 minutes a week, I wouldn't do it in five to 10-minute chunks. I

01:32:44.940 would do some 20-minute chunks or whatever. And what do we know about injury prevention

01:32:48.460 in that person? That probably they're going to get injured because they're going to find that

01:32:52.420 they're, no matter how metabolically unfit they are, they're probably going to find that they

01:32:56.320 gain metabolic fitness more quickly than they gain tendon stiffness and muscle strength and things

01:33:02.240 like that. So in a sense, that's even more reason to sort of take that guideline seriously. I mean,

01:33:08.480 I'm talking about running, which, because I love, you're less likely to get injured if you go cycling

01:33:12.400 or something like that. That's obviously, there's other ways of mitigating the injury thing. But

01:33:17.720 let me just cast some doubt on the J-shape thing. There were two main studies on which this whole J

01:33:25.040 curve hypothesis was founded. One was the Copenhagen study and one was the Cooper Clinic study.

01:33:30.680 The Copenhagen study, initially, it came out saying running is great and more running is better.

01:33:35.680 And then they reanalyzed it with a new co-author and they concluded that running too much or too

01:33:40.100 fast was bad. That was based on, there were two deaths in the group that ran too fast.

01:33:44.820 The confidence interval was essentially infinite, but there's a more serious problem. And it's one

01:33:49.160 that affects the Cooper Clinic data too, which is that when you have a big study of 50,000 people who

01:33:53.780 were just randomly selected, they're not all the same. They all have different characteristics. So you have

01:33:58.200 to find some way of adjusting for various characteristics. And without going too far

01:34:02.660 down the rabbit hole, basically, they statistically adjusted, initially at least, for things like

01:34:08.240 cholesterol levels, weight, blood sugar levels, blood pressure. It's meaningless if you compare

01:34:13.460 like the non-runners died sooner than the runners, but they were also 20 pounds heavier and had all these

01:34:19.480 other risk factors. So you want to equalize it. But there's a problem that if you equalize it,

01:34:24.300 you're essentially saying, well, what are the health benefits of exercise if you don't do any

01:34:27.940 exercise? Because the health benefits of exercise are precisely in helping you regulate things like

01:34:33.080 blood pressure and blood sugar and controversially, but I would say weight also. So to me, that was

01:34:39.100 statistical misconduct. You're saying if you take the people who exercise and you subtract,

01:34:44.000 you basically penalize them for having lower weight, better lipids, better blood sugar, better blood

01:34:50.340 pressure. So you bring them in line so that they're just as overweight and just have all the other risk

01:34:55.200 factors. Then you see this J curve. Now, when they actually published the data in a peer-reviewed

01:35:00.660 journal two years after it was presented, they'd eliminated that statistical method and the J curve

01:35:05.640 had disappeared. You no longer saw the J curve. I don't want to just dismiss and say, therefore,

01:35:11.700 there's nothing to see. I'm just saying that if we're talking about where the curve happens,

01:35:16.480 if you do that kind of statistical adjustment, which is the equivalent of saying, I want to know

01:35:21.720 whether smoking causes cancer, but I can't compare the smokers and non-smokers because the smokers have

01:35:27.620 more lung cancer. So let's artificially equalize it and pretend that the smokers just have just as

01:35:32.180 much cancer. Basically, in statistical terms, you can't adjust for a mediating variable, a variable

01:35:38.660 that's affected by the thing you're trying to measure. As you can tell, this is a topic I get

01:35:44.840 excited about. No, no, it is. And I've read what you've written about it, which is why I wanted to

01:35:48.540 bring it up. I have a slightly different take on it, which is less about everything you've said and

01:35:54.500 more of the practical issue. Because the practical issue is the one I get asked about a lot, which is,

01:35:58.960 am I exercising too much, right? This is the person asking the question. And so again, let's pause it for

01:36:05.280 a moment that 99% of people are not exercising too much and don't even possess the fortitude to exercise

01:36:14.020 too much, right? The pain tolerance isn't there. The obsession with exercise isn't there. So for

01:36:18.700 99% of people, we'd like to get them to exercise more or stay the same. We're dealing with 1% of the 0.99

01:36:25.200 population, many of whom I know and one of whom I used to be, that were kind of the hyper-exercisers.

01:36:31.160 Here's the bigger point I would make. It's probably less relevant whether or not they're spending too

01:36:37.540 many hours cycling, swimming, running, et cetera. Usually people in this sense, it's not the number

01:36:44.080 of hours they're spending. It's the portfolio allocation of how they're spending it that's

01:36:48.780 the bigger problem. It's that they're not well-rounded and they're not actually in pursuit

01:36:53.840 of longevity. So the reality of it is, is training for the Tour de France going to increase your

01:37:00.080 longevity? Absolutely not. No way. Like those guys finish the Tour anemic, osteopenic, their upper

01:37:09.360 bodies are emaciated. Their posture is horrible. There's nothing about that that is setting you up

01:37:16.560 to be an octogenarian that kicks ass. Nothing whatsoever. So their physiologic marvels, but 0.99

01:37:23.440 their health span sucks. So using that as an extreme, how would we extrapolate that to the 40

01:37:30.640 year old who just can't hang up the dreams of being a professional athlete, who's out there

01:37:36.340 running or riding or doing all of that stuff nonstop, but at the expense of maybe not doing

01:37:42.680 some Pilates to work on core strength. I hate the term, but you know what I'm just for people

01:37:46.880 understand what I'm saying, like not working on stability, not spending any time in the weight room,

01:37:50.740 really working on strength, not varying the intensity of their workouts to work different

01:37:55.200 energy systems. So to me, that's the bigger issue with people who are exercising too much. It's

01:37:59.660 probably not that they're at that little tip of a J that may or may not exist. It's that they're

01:38:04.840 squandering their time. It's like having all of this money, but you're invested. You have a lousy

01:38:09.520 portfolio. Yeah. Okay. I agree with a lot of that. One thing I'll say is the important question

01:38:14.500 you're implicitly asking there is what's your goal? What are you training for? Well, that's what I

01:38:18.000 said. Longevity. This was all predicated towards living a longer, healthier life,

01:38:21.420 not winning races or whatever. I would a hundred percent agree. If someone comes to me and says,

01:38:25.860 I want to optimize my exercise program for longevity. Like I said before, there's no way I

01:38:31.700 would tell them you should be training for a marathon. That's not because I think training

01:38:34.960 for a marathon is bad, but like you said, it's an opportunity cost of other things you could be

01:38:39.680 doing that a lot of other things you could be doing that would probably work better. So I think it's

01:38:45.520 really important to disabuse people of the notion that in order to optimize your health,

01:38:49.940 you should run a marathon. But where I bridle with the media coverage of that stream of research

01:38:56.260 is that that's different from saying that people who are training for a marathon because they want

01:39:00.840 to run a marathon or because they want to run a marathon as fast as possible should stop because

01:39:05.240 that's bad. So it's like of the category of people who have unhealthy behaviors, who we should

01:39:11.460 intervene to save them from themselves. It's like people who are training for a marathon to me are

01:39:15.840 not even close to being in the same category as people like me who are sitting at a desk for eight

01:39:21.220 hours a day or whatever the case may be. So it's like there's a difference between optimizing and

01:39:26.200 avoiding like serious problems. And the one other thing I should acknowledge is, and you alluded to it,

01:39:31.900 is there are other potential issues with lots of endurance training and arrhythmias is one of

01:39:36.340 them. And there's better evidence that that's a real thing. There may be downsides to training

01:39:41.460 really hard. On balance, overall, I would say I don't lie awake at night worrying about people who

01:39:47.120 are running 50 miles a week. Yeah, you're right. You should worry far more about people who are

01:39:52.660 eating poorly, smoking, who are stressed out of their minds and don't have coping mechanisms for

01:39:57.840 them. There's not many people that you should be worrying about more or less rather.

01:40:02.120 And if I think of the people I know who, let's say, run the equivalent of 50 miles a week or more,

01:40:06.860 I can't think of any of them who would say, I'm doing this because I think this is what I need

01:40:12.300 in order to optimize my healthspan or lifespan. They obviously hope it's healthy. But I think if

01:40:17.780 you're training for a marathon, most of them are doing it for competition, self-competition in a

01:40:22.420 way. And it sort of reminds me of something, you know, you discussed this a little bit, I think,

01:40:25.940 in your conversation with James O'Keefe, the what's great about tennis and badminton and volleyball or

01:40:30.320 whatever, what's the social element of it? And I think, sure, on average, running is a solitary sport.

01:40:35.660 But for me, it's my primary social outlet. It's where I meet my friends. It's where I get together

01:40:40.980 and catch up on the week on an easy run. So it's like, I think that's true for a lot of people who

01:40:46.660 once you get into that 50 miles a week, not for everyone, but for a lot of people, it's a social

01:40:50.980 outlet. It's pleasurable. It's a stress reliever. So if you take that away, I'm not sure it nets out

01:40:57.720 as positive.

01:40:59.020 One of the things that I think is, I don't know that we'll ever have an answer to the

01:41:02.060 question, but I think one of the challenges of trying to reconcile all of these disparate data

01:41:05.300 sources is it's all apples and oranges with respect to the metrics, right? It's you're comparing

01:41:10.400 hours of exercise a week to mileage run to true measures of fitness like VO2 max. I guess the question

01:41:19.500 is, and I've thought a lot about this, I'd be very curious to your thoughts. If you could reverse

01:41:25.400 engineer where you want your VO2 max to be when you're 90, what should it be? Because if you have

01:41:32.680 a sense of what your VO2 max should be when you're 90, you kind of know what it needs to be when you're

01:41:37.180 80, 70, 60, blah, blah, blah, blah, blah, all the way back. And at that point, it's not necessarily

01:41:44.340 about how fast you want to run a mile, though you may say, look, when I'm 90, I still want to run a

01:41:48.480 nine minute mile. I don't know. But it really starts to get into the activities of daily living and how much

01:41:54.300 pain are you willing to tolerate to walk up two flights of stairs with your groceries?

01:41:58.860 I hypothesize for me that when I'm 90, that the real risk is that I won't be able to get up out

01:42:03.780 of a chair more than that I won't have the VO2 max. And there are, I don't remember the exact numbers,

01:42:09.160 but there are thresholds of VO2 max below which they hypothesize that you can't remember if it's

01:42:13.140 like 18 or not, you know, maybe it's nine or something like that, where it's like, at this point,

01:42:17.380 you've crossed the sort of mortality and it's where we think you're going to die in a few years

01:42:20.220 because you can't do activities of daily living. So there is some research into that. But

01:42:24.120 for me, I can look at myself and say, you know what, Alex, far before your VO2 max is too low,

01:42:29.300 you're going to be the guy who falls on the floor and can't get up. And so, you know, again,

01:42:32.860 from a health perspective, that's why I said the next thing, if I had magic motivation dust,

01:42:37.600 it would be like, you need to put on some muscle mass. And for other people, it would be totally

01:42:41.600 different. There are people I know who don't necessarily exercise a lot, but who just have a

01:42:45.620 lot more muscle mass than me. And it's like, you need to make sure your aerobic fitness is taken

01:42:50.180 care of. And maybe you don't need to worry as much as me about muscle mass. So there's,

01:42:54.640 I mean, I agree, you figure out where you want to be and for all those different things. So I'm doing

01:42:58.020 exactly what you said, except I'm doing it for muscle mass. And I'm like, Ooh, this trajectory

01:43:01.360 is not good. And of course, part of that's predicated on the idea that we know there's an

01:43:04.860 inevitability of decline. So if you do nothing, you're going to lose X pounds of muscle per decade.

01:43:09.220 If you're lucky with a tailwind, if you train really hard, you might be able to reduce it to

01:43:14.940 this amount of loss. And if you really go crazy, you might even be able to keep it flat. But here's

01:43:20.660 the scenario under which that occurs. I assume there are pretty clear tables on what the decade

01:43:25.980 by decade drop of maximal aerobic output is. There are. I mean, the problem with the tables

01:43:32.620 is that they draw a nice smooth line. You lose, I think it's 9% per decade or something like that,

01:43:37.300 at least in the, once you get into your seventies, it gets steeper. There's a inflection point.

01:43:42.540 The sort of revised thinking is that that works on a population level. But what actually happens is

01:43:46.720 the decline is not that steep for any individual. But what happens is you have certain events in

01:43:52.320 your life. You have a knee replacement. You get an injury and you're stopped training for

01:43:56.260 six months and then you're hosed. Yeah. So either you have reduced activity for six months or you have

01:44:01.020 bed rest for a week, which can be disastrous. And you lose 7% in the course of a week and you only get

01:44:07.000 2% back. And so it's this punctuated decline. And so, I mean, that puts a lot of emphasis.

01:44:13.240 It sort of points to the idea of really taking care to avoid, to the extent possible, obviously,

01:44:18.000 to avoid these sorts of events, because you can actually, in the absence of those events,

01:44:24.180 the decline doesn't have to be that steep. You can hang on probably better than people used to think.

01:44:29.280 Can you say more about that? Because I don't think this point can be stressed enough.

01:44:33.000 Realistically, how much aerobic capacity, maximal aerobic capacity can a person lose with a couple

01:44:39.500 of weeks of inactivity? And what's the difference between being bedridden versus going on vacation

01:44:46.100 to Europe where you're not quote unquote training, but you're still walking every day? Neither of those

01:44:51.040 is exercise per se, but one is active and one is complete inactivity.

01:44:56.240 Bed rest is terrifying. There's a guy named Luke van Loon in the Netherlands. His focus is muscular

01:45:01.060 strength, but he's done a bunch of bed rest studies. I saw him give a talk once and he had

01:45:04.760 this great anecdote about they'd spent a whole bunch. It's really hard to get old people to 0.99

01:45:08.840 put on muscle, right? But they just managed to finish this two and a half year study where they

01:45:12.640 got, I can't remember, some fairly large number of septuagenarians, octuagenarians to do strength

01:45:17.440 training. And they'd put on like two and a half kilograms of muscle, which is a huge victory.

01:45:21.400 And they were feeling really good about it. And then the results came in for their one week bed rest

01:45:26.140 study. And they'd lost like 2.6 kilograms of muscle in one week. So it's like they did this

01:45:32.140 like Herculean effort to shepherd these people through strength training for a long period of

01:45:37.520 time with full support. But man, whatever it is, you know, grandma gets pneumonia and is in hospital

01:45:43.740 for a week, bam, she's lost a year of training or whatever the case may be. So I don't have the

01:45:49.080 numbers at hand for V2Max. I think it's like up to 10 to 20% in that range if you stop training for a

01:45:53.860 month. It depends where you're starting though. Like it's like, if you're well-trained for a short

01:45:58.040 period of time, you'll lose it quickly. If you haven't been training, then resting doesn't make

01:46:01.960 any difference. And if you're well-trained for a long, long period of time, then you have structural

01:46:05.860 adaptations that are going to take a lot longer to disappear. So there's no one number for anyone.

01:46:11.320 And the one thing I would add is that this is not a recommendation that you should never take a

01:46:17.000 break from exercise, that you should be obsessive, train 365 days a year. Certainly if you're training

01:46:22.040 hard, like if you're training as a marathoner, say, man, you should take a week or two off.

01:46:27.620 And off doesn't mean bed rest. It means play a couple games of tennis, go for walks, chill out,

01:46:31.860 go for some bike rides or whatever. So you shouldn't be terrified of missing a day, but you should be

01:46:37.140 terrified of bed rest. I mean, Luke Van Loon, one of the things he said is like, if you're in bed rest,

01:46:41.760 hospitals should be forcing you, if you're at all possible, to walk down the hallway to get your meal.

01:46:47.200 Even just walking down the hallway is infinitely better than not moving at all.

01:46:51.120 God, never more sort of relevant than what we're seeing today with so many people in hospitals and

01:46:56.660 a lot of the isolation stuff that's going on. Let's go back to something you said about strength.

01:47:02.420 What do you think matters more, strength or muscle mass?

01:47:05.480 There's a study I wrote about recently. I would hesitate to claim it as the absolute truth, but

01:47:09.780 I think it put together like six different cohorts with a total of about 50,000 people. So pretty good

01:47:13.960 data. And they found that strength was actually a better predictor than muscle mass.

01:47:18.160 So it's better to have the functionality to be able to push yourself up out of the chair

01:47:23.100 than it is to have a bunch of muscle if you're not good at using it. I'm sure that's maybe not

01:47:27.140 true at the margins. If you lose enough muscle mass, then you become limited by your actual muscle mass.

01:47:32.040 But I think for a lot of people, they have enough muscle mass, but they're untrained.

01:47:34.820 The neuromuscular connections are not optimized. And so they're just, they're not strong,

01:47:39.220 even though they have enough actual flesh there.

01:47:41.740 And was that for all cause mortality? Yeah.

01:47:44.780 So that's interesting. That doesn't sound like a crazy conclusion. I generally try to say, look,

01:47:50.600 I think both of these things are important for different reasons, right? I think of strength

01:47:54.240 as, as you described it, it's that functional, it's the difference between the person who slips

01:47:58.080 down the flight of stairs, but has the strength to grab the rail and prevent that, you know, from

01:48:02.920 being a lethal injury or the type of injury that puts them in the hospital for a month. You know,

01:48:07.660 grip strength is just so highly correlated at least with survival. And I think a lot of it has to do

01:48:12.980 with that kind of stuff, getting up out of the chair, getting up off the floor. At the flip side

01:48:17.000 of that is I think muscle mass speaks to some of the other physiologic things like glycogen stores

01:48:23.160 and glucose disposal and glucose homeostasis in general and insulin sensitivity. So again, I rail

01:48:30.160 against the idea that people say, I just, I'm okay being strong. I just don't want to be big. And it's

01:48:34.400 sort of the myth of accidental muscle, you know? I wish I had that problem. It's like, oh, I looked

01:48:39.200 at a gym and I accidentally put on 10 pounds of muscle. Yeah, yeah, yeah. I hear people saying

01:48:42.540 that and I'm like, yeah, I wouldn't worry about that. Anything else about injury? I mean, you've

01:48:47.100 written a lot about this in terms of different competing theories around injury. And do you think,

01:48:51.880 how much do you think it varies by sport? And, and, and I guess most importantly, what is the

01:48:55.980 implication for people who tend to get injured in life? They're walking down the street and they

01:49:01.480 pull a calf muscle versus they're out there doing your tempo run.

01:49:06.280 I've been willingly or unwillingly embroiled in lots of debates about injuries over the last

01:49:10.460 decade and a half. And a lot of them focus on things like running shoes, the proper running form

01:49:15.900 is the height of your insole going to affect your risk of injury. And that stuff's fun. And it's not

01:49:21.160 zero impact, but there's a guy named Ben O'Nigg, who's a sort of famous biomechanist,

01:49:27.200 who's done a lot of work on running injuries and stuff. And his take in one of his studies

01:49:32.220 was that, look, 80% of running injuries are a result of what he would call training errors.

01:49:38.000 So yeah, it's, it's nice, you know, there's 20% to work with on shoes or whatever,

01:49:42.960 prehabilitation and balance, yada, yada, yada. Most of what we need to worry about is doing too much

01:49:48.200 too soon. And that's an oversimplification. But certainly when we're talking about overuse injuries,

01:49:52.680 I'm not talking about like getting tackled on the football field. I really think for people who

01:49:58.040 are starting out or ramping up an exercise program, that patience is so important. And

01:50:03.820 that understanding that you will probably overestimate what you can accomplish in the

01:50:07.720 short term, and you'll probably underestimate what you can accomplish in the long term.

01:50:12.420 And if you fall into that trap, you're dramatically raising your injury risk because you're going to

01:50:16.520 try and ramp up too quickly. Because again, you can gain metabolic fitness more quickly than you can

01:50:20.340 alter the structure of your joints and ligaments and things like that. So if there's one takeaway

01:50:26.680 message, it would be like, it's not about the magical gadget or the new way of running or the

01:50:33.000 measuring device. It's like, just be patient, be smart. You know, you get home, you have something

01:50:38.820 that's aching. You don't want to miss the next day's session. And you don't want to become,

01:50:42.920 it's always a balance, right? Between being, am I being lazy or am I being safe? Well,

01:50:47.860 you want to err on the side of safe, certainly until you start getting a better handle on which

01:50:53.140 aches and pains are normal and which ones aren't. We can get into things like balance training or

01:50:59.420 training load monitoring, you know, acute versus chronic. Yeah. Let's talk about acute versus

01:51:03.800 chronic load training. I mean, I used to have a program called Training Peaks that would track

01:51:06.980 this for me. So it saw every single day, how many miles I rode. And it actually did it more by

01:51:12.300 kilojoules than miles. So it was total energy expenditure. But if you were giving someone,

01:51:17.860 some guidance, some rules of thumb, if they were becoming active, and we don't have to get into

01:51:22.400 the formulas, but just using the principles of acute versus chronic load balance, how would you

01:51:27.560 help them think through everything you just said with these metrics? The rule of thumb that they

01:51:32.980 used to teach runners is the 10% rule. Never increase your mileage more than 10%. And it's a

01:51:37.040 rule that makes no sense at the margins. Like if you start by running one mile, then you're never

01:51:41.960 going to get above five miles in your lifetime or whatever. But basically the idea is trying to avoid

01:51:46.820 the too much too soon problem. Now, this idea of an acute to chronic workload ratio is a sort of

01:51:51.940 more sophisticated version of that. And the idea is how much are you doing now versus how much is

01:51:56.340 your body used to? And the way that the academic papers do it is what's your weekly load, whether

01:52:02.340 you do it in joules or miles or minutes, and what's your average weekly load over the last four

01:52:06.980 weeks? And this is when they started publishing this, I was like, hey, that's I designed my own

01:52:11.080 training log back in the 90s and printed it out. The two things I had at the bottom was

01:52:14.720 kilometers that week and four-week average kilometers.

01:52:18.780 Why did you settle on four weeks, by the way, as opposed to three weeks or five weeks? How did

01:52:22.340 you arrive at that? Do you remember?

01:52:24.180 Yeah. There was no deep thinking involved. It was basically a week versus a month.

01:52:29.160 And you can argue it that you need a decent amount of time because otherwise you have one week where

01:52:34.140 you miss a couple of days due to injury, and then all of a sudden your four-week average is totally

01:52:36.900 skewed, or if it's a three-week or something. And five weeks, six weeks, at a certain point,

01:52:41.780 you're moving so far back that your body no longer cares what you were capable of doing

01:52:45.600 eight weeks ago, or at least not as much. So four weeks, it's just a, it's kind of a,

01:52:50.660 if you've done something for four weeks in a row and you're feeling okay, then you can kind of assume

01:52:55.780 that, yeah, your body's able to handle that load. So then this allows you, it's just a quick way of

01:53:01.600 seeing if there's any deviations. It's like, this week I did 50% more than my four-week average.

01:53:07.520 That's a bad, bad sign. It doesn't mean you're going to get injured. There's all sorts of

01:53:12.920 contextual things you have to consider in it. But having that as one input into your larger matrix

01:53:18.160 of all the things that you're considering, like, do I feel any aches and pains? What's my absolute

01:53:23.880 load? Not just the ratio, but is this more than I've ever done before? You consider all those things.

01:53:28.600 And I think that acute to chronic ratio, or just to put it more simply, keeping track of how hard

01:53:34.340 you're going now versus how hard you've been going in the previous month, or how much you've

01:53:39.740 been doing, let's say, is useful. Now, I should add that there's controversy in the literature.

01:53:44.280 There's a bunch of people who say that the supposed predictive value of acute to chronic

01:53:47.840 workload ratio is a statistical artifact. It may be, it may not be. I'm not too worried about that.

01:53:53.520 To me, this is not about statistical predictive power. It's just about keeping an eye on trends,

01:54:00.540 and knowing if you're way out of whack with what you've been doing before. And as a general rule,

01:54:05.320 you know, let's say if you're 20% higher, that's a time to start making sure you know what you're

01:54:10.980 doing. Yeah. And backing it off maybe that next week. Yeah. Unless you have some compelling reason

01:54:16.440 to think that you can handle that. If you're exceeding 20%, then yeah, be cautious and ideally

01:54:21.920 back off. So you alluded to it earlier, but let's talk a little bit about high intensity interval

01:54:26.160 training. It's getting a lot of attention today. Obviously, most people are familiar with what a

01:54:31.600 Tabata is, though. Tabata himself is not the guy that actually designed the protocol, but everybody

01:54:36.840 still refers to it by his name. Where do you think this fits into the hierarchy of, again, not a specific

01:54:43.660 athlete who's training to run the mile or the marathon, but a person who's trying to be healthy?

01:54:49.300 How much of a shortcut efficiency gain is it? Again, let's use the Tabata interval as an example,

01:54:54.780 where you're going all out for 20 seconds, resting for 10 and repeating it eight times.

01:55:00.120 And by the way, wouldn't we argue from your research in Endure that you can't technically

01:55:05.240 go all out for 20 seconds? I've started when I do all out intervals, I now limit them to 10 seconds

01:55:12.000 because I actually started paying attention and realizing I was subconsciously pacing myself at

01:55:18.300 20 second all outs. But anyway, I don't know what you think about that idea. But I remember reading

01:55:24.200 in your book, wasn't it the case that we technically can't go all out for 20 seconds?

01:55:29.540 It certainly doesn't seem that way. And you know, like Usain Bolt or world-class sprinters don't go

01:55:34.180 as fast. I mean, it's complicated by the curve. They don't set world records en route to 200 meters.

01:55:39.820 They're pacing themselves even for 20 seconds. I just have to tell one quick story about Tabata.

01:55:44.880 I was at a conference at the poster session where the researchers are in front of their posters

01:55:48.520 talking about it. And it was a research from the McMaster group, which has popularized high

01:55:54.040 intensity interval training. And one of the postdocs was there explaining his high intensity interval

01:55:58.200 training research. And someone came up and asked him a question and handed him his business card

01:56:03.120 at the time. And I noticed the postdoc, he looked down, as he was answering the question,

01:56:07.080 he glanced down at the business card and his eyebrows just went like halfway up his forehead.

01:56:10.540 And I peeked over and it was like, oh, that's Tabata. That's cool. I didn't realize this was a real

01:56:14.520 person. So he was there asking questions about intervals. Anyway, where do I think intervals

01:56:20.380 fit? I think they're super important. When circa 2008, when high intensity intervals started to be

01:56:26.080 a big buzzword, I was like, how is this a buzzword? That's how runners train. One of the studies out of

01:56:33.520 the McMaster group was like, let's do 10 times a minute. That's the Roger Bannister. That's how he

01:56:38.620 broke the four minute mile in 1954. What's new about this? But it was new to a lot of people. A lot of

01:56:43.560 people were like, I need to go 45 minutes. I need to go an hour. I need to do this. I need to do that.

01:56:47.640 I guess what I was really getting is the compression of that, right? It's the, I don't know if you saw

01:56:52.520 this. Well, I'll let you finish this, but then I'll bring it to where I'm going, which is what

01:56:56.420 are the limits of how much you can shrink that? How low can we go? Yeah. Yeah. How low can you go?

01:57:00.960 But yeah, but keep going with it. Yeah. I'll just say that as two general points. One is that

01:57:04.340 as a runner, one thing I know is that you will never ever run fast relative to your abilities if you

01:57:10.900 don't do interval training. The second thing I would say is you probably won't run as fast as

01:57:15.520 you could if you only do interval training. Now, some people do do only interval training,

01:57:19.640 but that's usually they're doing it so slowly that it's not different from just doing a sustained

01:57:23.720 thing. So to me, when you look at the studies, it's like, let's compare eight weeks of three

01:57:29.200 interval workouts a week to eight weeks of three 45 minute sustained sessions. It's like, okay,

01:57:35.420 that's interesting. It's useful to know, but I really don't think that's what is optimized and

01:57:41.820 what we should be comparing it to. What about one short sprint interval session, one medium

01:57:45.800 interval session, and one 45 minute session or some portfolio? Because there's pretty clear

01:57:51.600 evidence that you can get to the same or some of the same health outcomes. You can get the same

01:57:56.240 improvement in insulin sensitivity, say, but the mechanisms may be different if you're doing a

01:58:01.120 sprint interval session versus, or if you're doing sprint interval training versus sustained

01:58:05.540 training. And so it's like, well, if you've got two different mechanisms, let's hit them both.

01:58:09.080 Because presumably we're going to get a little one plus one is going to be at least equal to,

01:58:12.360 we know, 1.2 or something like that. So I would 100% recommend to anyone that they should be

01:58:18.380 including some form of interval training in their routine if they're interested in health or

01:58:22.660 performance. I wouldn't necessarily recommend it as the only thing unless that's what they want to

01:58:27.140 do. I would put it as part of a portfolio. And as far as the sprint stuff goes,

01:58:30.920 we can talk about this, but it's like, it has been funny to watch the, it's not like one upmanship,

01:58:35.780 it's one downmanship. How short can we make? It's like, okay, I thought about interval training

01:58:40.520 for a millisecond last night. Look, I got fitter. It's amazing. Well, that's only a slight exaggeration

01:58:46.460 from a study that came out recently from here in UT Austin. Ed Coyle, who is a physiologist and

01:58:52.800 published a study looking at four seconds all out, 56 seconds of rest. So it's every minute on

01:59:00.860 the minute, but only four seconds all out. And this was done, I believe for 15 minutes. And then

01:59:06.380 they progressed to basically four seconds all out twice a minute. So you go four seconds all out,

01:59:12.660 26 seconds of rest, repeat, you know, for 20 minutes, something to that effect.

01:59:18.360 Here's my take on these things. It comes down to a concept you raised earlier, which is there's an

01:59:23.960 opportunity cost to them. They're usually comparing that to doing nothing. And is that better than

01:59:30.680 sitting on the couch? Yes. But if you gave me 40 minutes a day, could I come up with a more

01:59:38.260 efficient way to get a benefit? I probably could. And then it becomes a question of what's the efficacy

01:59:44.920 versus effectiveness of this intervention. And I think that's the other piece of this, right?

01:59:49.660 Which is, I think people like you and I like exercise so much that we get to focus all of our

01:59:57.340 effort or interest on efficacy. What is actually going to do the best, produce the best results when

02:00:05.800 adhered to perfectly. But I accept the fact that many people don't enjoy exercise and therefore the

02:00:12.040 real world applicability of a problem becomes its effectiveness. It's not what can be done in a

02:00:17.360 laboratory for six weeks when you're a paid subject. It's what are you going to be willing to do on your

02:00:23.640 own when you have to rely on your own sprinkling of motivation dust day in and day out. And so I guess

02:00:31.260 on some level, that's where I've become a little bit more accepting of the fact that, hey, if people are

02:00:36.720 willing to do shorter interval workouts, provided they don't get injured, that's always the fear I

02:00:43.000 have when people jump right into these high intensity interval workouts without any of the

02:00:48.180 foundational strength that goes into it. If the alternative is doing nothing, well, then it's

02:00:53.060 better. But I guess secretly, I just hope that I can convince people that they're better off

02:00:58.140 learning to love exercise, which again, I think is why a book like yours is so great, right? It explains

02:01:03.460 how we evolved. And the more we can think about reconciling what we are today with what we spent

02:01:11.200 a million years becoming, perhaps the less foreign that feels. So I think you've put your finger on

02:01:17.240 exactly the issue, which is it's, yeah, it's not about what does better in this lab context. It's what

02:01:23.840 will people do? And I actually, I'm a little bit skeptical that four seconds at the intensity that you have to

02:01:31.640 do those intervals is more acceptable to the average person than let's say one minute.

02:01:39.380 So going back to a little history on the HIIT stuff, the first HIIT protocol was Wingate tests,

02:01:43.660 which is like 30 seconds all out. And anyone who's done a Wingate test, you know, if you do it in the

02:01:49.220 lab, they're screaming at you. It's like, you know, we're going to shoot your mother if you don't go as

02:01:52.900 hard as you can. And you get every, people puke after Wingate tests. So the original protocol was 0.96

02:01:58.260 four Wingate tests with seven minutes rest, because that's how hard they are. It's like what

02:02:03.740 we were saying earlier about how hard an 800 meter race, a two minute race can be compared to like a

02:02:07.860 marathon. You can really suffer in those 30 seconds. And so when they're like, well, okay, it works in

02:02:14.600 the lab, but in real life, what's, what are people going to do? Their answer initially wasn't like we

02:02:18.600 should make it shorter. It was, well, the intensity that people can actually get to in real life,

02:02:23.540 we should, that's where the 60 second on 60 second off protocol came from. Cause it's like,

02:02:27.520 it's easier for people to accept 60 seconds pretty hard than it is to expect them to imagine

02:02:34.120 the, you know, homicidal drill surgeon behind them, yelling at them to get all of it out of

02:02:39.560 themselves in 30 seconds. Now you're going down to, let's say there's been 20 seconds. There's been

02:02:43.180 10 seconds. There's been four seconds. It's hard. It takes a lot of motivation. You have to be

02:02:48.640 a hundred percent on to get the most out of this four second or 10 second or whatever

02:02:53.920 interval. So there's a lot of debate understandably about like, okay, well, which is it that people

02:03:00.280 will do? Would they rather do 20 minutes at medium or 40 minutes easy or four seconds hard? I think

02:03:07.040 there's a lot of debate because there's different, there's a lot of different people, people like

02:03:10.100 different things. And some people are love that, that, that power thing. And that that's great.

02:03:14.940 And, and, and again, like you said, it's, I don't think it's as good as doing a mixed portfolio of

02:03:19.220 things, but I think it's, it's pretty good. And if they'll do it, that's great. But I, I think the,

02:03:24.200 the, the assumption of this race to the bottom of how, how short can you make the interval

02:03:27.800 is that people like it more. I'm not sure that's true for everyone.

02:03:31.300 I love your comment about, I thought about high intensity intervals for a second last night.

02:03:37.640 I will say this. One of the things that I think is a big challenge here is most people aren't clear

02:03:42.040 on the why they just want to do the, what, you know, this is sort of the going back to my pet

02:03:47.860 peeve of people, confusing strategy for tactics. I think if people don't understand the benefits of

02:03:53.880 the different types of exercises and why you're doing them, you know, actually reverse engineering

02:03:59.120 what the purpose is. So you're thinking about the 90 year old version of you in a chair, he needs to

02:04:04.960 get up. Well, that gives you the motivation to do strength training. And if you didn't have

02:04:09.600 the aerobic conditioning, you'd start to think, well, once I get up out of said chair, what do I

02:04:14.280 want to do? Oh, I might actually want to go and walk around the block with my grandchild. Oh, well,

02:04:20.400 what would that involve? Well, at my house, there's a hill and that hill goes from here to there. And

02:04:25.700 what if I want to stick them in a wagon and pull them? Like that's actually going to require aerobic

02:04:30.980 capacity. And that hill is pretty short. So it's actually going to be pretty intense. Like it actually

02:04:35.560 requires a near maximal effort for me. And so I just think that the more people can tether what it is

02:04:41.760 they are doing this for to something real, it becomes a little easier to do these abstract workouts

02:04:48.400 because otherwise, like, what are we doing, right? Like once you stop competing in something, which is,

02:04:53.360 you know, a fraction of the percent of the population, all this exercise stuff becomes abstract. And

02:04:58.280 frankly, the practice of medicine doesn't do a great job communicating the why, right? I mean, most,

02:05:03.780 most people know they should exercise, but I don't think they've really had a great explanation as

02:05:08.700 to, for example, fighting cancer when you're fit is probably a lot easier than fighting cancer when

02:05:15.800 you're not fit, simply based on the energetics of your immune system. You know, most people don't know

02:05:21.560 that. And therefore it's a bit abstract why they should be exercising so much. Yeah. I mean, you could say

02:05:27.320 the definition of insanity is telling people that exercise is good for them yet again, and hoping that

02:05:32.380 that on its own is going to convince people to exercise. It's clear that doesn't work. So I think

02:05:36.480 what you say is right. You need to make it visceral and to relate to things that people care about. And

02:05:41.600 so that people care about different things. So you have to understand what each person cares about

02:05:45.060 and then find out what the right exercise for them is that's going to connect for them.

02:05:49.220 Last thing I want to ask you about, Alex, is basically the merger of the two careers you've had.

02:05:54.760 I've probably been pretty critical of your profession, which is science journalists or

02:06:02.080 journalists who cover science. Let's put it that way. Because truthfully, I think most of them are

02:06:06.960 really bad. And I think many of them actually border on negligent. And I think they cause on some

02:06:14.140 levels more harm than good to the public. Obviously, I don't put you in that category. And there are many

02:06:18.980 people I don't put in that category who I think are excellent at science journalism, but they're really in the

02:06:23.600 minority. So most of the sensationalized headlines, and frankly, even the news stories that just don't

02:06:30.080 have the detail that I think should at least be covered in a news story, given the understanding

02:06:35.080 that very few people are going to go back to the primary source and read it, places an enormous

02:06:39.360 responsibility on scientific journalism. Do you think there's a systematic way to make this process

02:06:44.960 better? Oh, that's a heavy question. My perception as the problem, and this is self-serving since I'm a

02:06:51.020 science journalist, is that journalism now follows the audience. And I started out in 2006, let's say,

02:06:59.240 just at the point where news organizations were first starting to be able to see how many people

02:07:04.780 clicked on a story. And this was one of the great catastrophes of journalism in some ways,

02:07:10.560 because it's terrifying to find out what people click on. It's unhealthy for the news organizations

02:07:16.740 to find out what people click on. I can remember, so the big newspaper in Canada is the Globe and

02:07:21.360 Mail. And early on, as newspapers went online, they started to, people realized it's kind of nice to

02:07:27.440 have, what are the top 10 most clicked on stories? So then you can go and, and I remember when the

02:07:32.240 Globe, as far as I remember, I don't know the exact timeline, but shortly after they introduced this

02:07:36.580 feature, I was like, how is it that the top 10 stories on the Globe and Mail website, like three of

02:07:42.840 them are about Britney Spears. It was just like, the Globe and Mail is supposed to be the kind of

02:07:47.980 highbrow newspaper in Canada. And it looks like it's a bunch of simpering morons who are clicking. 1.00

02:07:52.820 But like, then I look at what I click on sometimes, and it's like, sometimes you're just tired and you 0.99

02:07:56.220 click on the sort of craziest thing. So anyway, sorry, I'm drifting off the point here, which is that

02:08:00.380 to encourage good science journalism, you need people to read good science journalism.

02:08:05.520 And I think newspapers are realizing that following the audience has turned out to be a bad move,

02:08:10.040 because they've ended up losing the trust in audience. But by giving people what they thought

02:08:14.320 they wanted, you ended up basically giving them crap, and then having people recognize that they 0.99

02:08:19.440 were being fed crap, and then rebel against it. So where I started my sports science journalism career, 0.94

02:08:26.560 in some sense, was I started a blog on WordPress in like, I don't know, 2008 or something,

02:08:32.020 where I was just like, you know what, I can't write this in a newspaper article. But on this blog,

02:08:37.940 I know there are people who are interested in the details of what the study says, I'm going to have

02:08:41.200 the key figure from the study. And I'm going to say how many subjects there were and what their

02:08:45.060 characteristics were, and what the intervention was. That's the blog that became, it got taken

02:08:50.220 on to Runner's World in 2012, and then moved over to Outside in 2017. It turned out there was an

02:08:54.500 audience for that, which is encouraging. So I think, I guess I'm not answering your question at all,

02:08:59.180 which is how do you fix it? But news organizations aren't going to insist on scientifically qualified

02:09:05.500 journalists, unless there's repercussions or feedback when there's bad journalism. And I

02:09:13.500 think the initial signals were the opposite. They were actually getting feedback that the less

02:09:16.900 complicated it was, and the more sensational it was, the more feedback they got. To try and actually

02:09:23.480 give one concrete answer to your question is that the move away from advertising and towards

02:09:28.940 subscription-based models, I think has helped and hopefully will continue to help move away from

02:09:37.400 like, just let's do what's most sensational to let's do what's most, let's give people a filling meal

02:09:41.380 that they're not going to be hungry 10 minutes later. So maybe that trend is a good one in some ways.

02:09:47.340 And look, I don't know that I expected you to have an answer because this is a question I've thought

02:09:50.640 about for a decade, actually, probably around 2011 is when I started really becoming frustrated with

02:09:57.520 journalism and science, which is not to say that's when it started. I think that's just when I began

02:10:02.560 to notice it enough and realized that the signal to noise ratio had fallen to zero. And if you ask my

02:10:09.460 friends, there's no better way to drive me nuts than just to forward me a headline and without even a 1.00

02:10:14.660 question, like as though somehow I'm supposed to read this idiotic headline and know what your question 0.99

02:10:18.640 is of me. But look, I still get three of those a day. So anyway, Alex, this has been awesome. I 0.99

02:10:24.080 have, like I said, I've wanted to sit down with you for a couple of years since I read Endure and

02:10:28.160 I can't recommend it highly enough. I find it riveting. I think you're a, you're a, you're a great

02:10:32.900 writer and a great storyteller. And that that's to me, I think one of the gems of reading a book like

02:10:37.360 that is you, you're reading about science, but you're also reading it in the context of amazing

02:10:41.600 stories, personal stories, stories of other individuals. So thank you very much for that

02:10:46.200 contribution and all of your amazing stuff on outside, which I, again, I can't get over how

02:10:50.700 prolific you are. And it's just, it's, it's gem after gem. Thanks, Peter. It's been a real privilege

02:10:55.680 to have a chance to talk to you and I've appreciated your work over the years. And I really, I'm glad we

02:10:59.820 had a chance to talk and I'm just sorry. My answers were so rambling. Not at all. Thanks, Alex.

02:11:05.280 Okay. Thanks, Peter. Thank you for listening to this week's episode of The Drive. If you're interested in

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The Peter Attia Drive - March 01, 2021

#151 - Alex Hutchinson, Ph.D.： Translating the science of endurance and extreme human performance

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