RILEY GAINES PODCAST： Exploring the Science： How Testosterone Impacts Athletic Performance
Episode Stats
Words per Minute
151.8474
Summary
In this episode, Dr. Carol Hoeven joins me to talk about intersex and gender ideology in the sports world. She is a PhD from Harvard and served as a professor for over 20 years. In this episode we discuss intersex, gender ideology, and the science around intersex.
Transcript
00:00:03.400
Break through the busiest time of year with the brand new Peloton Cross Training Tread Plus.
00:00:09.700
With real-time guidance and endless ways to move,
00:00:12.280
you can personalize your workouts and train with confidence.
00:00:21.620
Explore the new Peloton Cross Training Tread Plus at onepeloton.ca.
00:00:40.860
She is going to be helping us understand how to follow the science, right?
00:00:49.560
where ultimately she ended up teaching for 20 years.
00:00:55.860
So Carol, Dr. Hoeven, thank you so, so much for coming on.
00:01:06.360
which never in my wildest dreams did I think we would ever do that.
00:01:13.140
Would you start by just kind of letting the listeners know about you,
00:01:19.780
and kind of what your knowledge in this whole gender ideology really is?
00:01:26.300
And first of all, thank you so much for having me.
00:01:43.500
First of all, I studied wild chimps in Uganda before I came to Harvard.
00:01:47.220
And that's what really allowed me to see sort of in the raw,
00:01:54.120
the difference between male and female animals.
00:01:57.860
And the males are just a lot bigger and stronger and more aggressive.
00:02:03.640
And that's a pattern that is relatively consistent across a wide variety of animals,
00:02:09.540
So that got me really interested in testosterone.
00:02:13.140
So when I came to Harvard for my PhD, that's what I studied.
00:02:16.560
And I really focused on certain aspects of cognition and how the sexes differ
00:02:26.040
Um, so then I just stayed on at Harvard and ended up as of, um, last year, uh,
00:02:38.420
co-directing the undergraduate program in human evolutionary biology and also teaching.
00:02:46.520
And I taught about hormones and sex differences for over 20 years to, um, Harvard undergrads.
00:02:56.660
So, so clearly you're very qualified to talk about, um, the topic that,
00:03:01.240
that has seemed to affect so many now, which is of course the, the trans issue, trans debate,
00:03:06.700
which shows you that they don't really have our best interests.
00:03:10.560
And when I say are, I don't mean just female athletes.
00:03:14.380
I mean, us as a, as a human, as a species, they don't have our best interests at heart,
00:03:23.300
Um, before we get into kind of like the, the testosterone effects, the, the different
00:03:29.060
levels and stuff that different sporting governing bodies are covering, or I guess the guidelines
00:03:35.900
I wanted to start with you because you mentioned two sexes and, and pushback.
00:03:40.020
I hear all the time, again, traveling, whether that's testifying at the state level, the federal
00:03:50.080
I constantly hear that there are three and people are indicating that intersex, again,
00:03:54.840
um, DSCs, and I'll, I'll let you go to just briefly an overview of what that really is.
00:04:01.320
Is this a third sex or is this a combination of the two sexes?
00:04:08.820
And this misunderstanding is totally under is, is understandable.
00:04:12.880
So intersex, first of all, as a term is not particularly helpful in my view, the language around these
00:04:22.240
either differences or disorders of sexual development, DSD is sensitive and people disagree about the,
00:04:32.720
Uh, but intersex really implies that one is between two sexes.
00:04:38.740
And that's why I think it's not helpful because in the overwhelming majority of these, I'll just,
00:04:45.300
of these DSDs in the overwhelming majority, 90 over 99%, there's, uh, they affect either males or females.
00:04:58.100
I should say, I said something about what the, what male and female mean.
00:05:02.680
And it's important to understand that because then you can understand why there isn't a third sex.
00:05:07.660
So it's really, if you look across all of these different species, look across sexually reproducing species,
00:05:14.480
there are two reproductive classes and the way that, and we're one of them and obviously we're mammals
00:05:22.320
and, uh, it's very clear in mammals that they're, um, males and females who must combine their gametes
00:05:33.000
There's no case of a third gamete in any species.
00:05:38.960
There are like clownfish that can change sex throughout the course of their lives.
00:05:44.600
There are flatworms that can produce both gamete types.
00:05:48.400
Uh, so those examples only illustrate, still illustrate that there's only male and female,
00:06:00.160
You cannot change sex over the course of your life and you, and there's no cases.
00:06:05.680
And I've looked very hard and many people have looked very hard.
00:06:08.440
There may be one questionable case in the literature in which an individual produced viable sperm
00:06:22.220
If you understand the endocrine system and the control of gamete production, again, that's
00:06:27.760
It's almost impossible for a, um, testis and an ovary at the same time to be stimulated by testosterone
00:06:39.700
If that were the case, then that person would, you could potentially say maybe that person
00:06:44.640
is truly intersex is both, both male and female, but that doesn't mean that's a third sex.
00:06:51.240
It's just has female traits and has male traits.
00:06:59.680
There is the probably, uh, a calm, one of the most common, uh, DSDs in males who are competing
00:07:13.920
And there are some prominent examples of these, um, athletes.
00:07:19.860
They're overrepresented by about 140 times compared to the prevalence in the, uh, general
00:07:26.460
They tend to be overrepresented in, uh, elite sports because these are males who, I won't
00:07:35.260
get into the endocrinology, but I'm happy to, uh, if you want an explanation, these are
00:07:39.560
They can't produce a certain enzyme that converts testosterone into DHT, which is a more potent
00:07:50.600
That androgen is necessary for the development of the penis in utero.
00:07:55.100
So if it's not present, sort of the default state is something like a vagina, which does
00:08:01.620
not connect to a uterus because there is no uterus in males.
00:08:05.280
Although it's possible if you don't have androgen action that you end up with external genitalia
00:08:15.940
There's internal testes that never descend into a scrotal sac.
00:08:20.120
This is called 5-alpha reductase deficiency syndrome or 5-ARD.
00:08:25.420
It, it appears that this is, uh, what Castor Semenya, the DSD that Castor Semenya had, and
00:08:33.860
there's pretty good, uh, documentation on that.
00:08:37.320
And the problem arises because this person is, if, uh, born in a, you know, potentially remote
00:08:46.880
area without, um, sort of modern medical care, these people might be sexed as female at birth
00:08:59.480
Uh, but most of them actually end up transitioning in puberty to living as a male because they feel
00:09:07.220
They tend to feel like a typical male because they've had masculinization of the brain in
00:09:12.940
So that is an example where people will say, look, if this person has something that looks
00:09:19.320
like a vagina, well, that's a female characteristic.
00:09:26.320
No, that is a male who has an underdeveloped, uh, underdeveloped, say, external genitalia because
00:09:36.240
Uh, so that is the body plan to produce gametes and their evolutionary biologists understand
00:09:42.440
why that's important because it explains if you have the body plan to produce gametes, you
00:09:47.860
have different sexual and reproductive strategies than those of us who have body plans to produce
00:09:54.140
We have different kinds of hormones, which are reproductive hormones, testosterone and estrogen.
00:09:59.660
Those hormones shape not only our reproductive system, but also our brains and our secondary
00:10:06.240
Like either having, you know, breasts and wide hips and more fat or having a larger body
00:10:13.340
size, more muscle, um, and facial hair and a deeper voice.
00:10:20.840
And those are all about the differences in hormones.
00:10:24.020
So people, so males with that particular DSD have all of those other masculine traits.
00:10:30.440
And, uh, so intersex, first of all, is not a helpful term.
00:10:37.740
You can be a female and have high testosterone.
00:10:41.440
We all know that there are females who transition to living as males and they raise their testosterone.
00:10:48.020
There's still females who just have high testosterone.
00:10:51.020
You can be a female or, uh, who has a penis, something that seem, you know, looks like, or
00:11:00.360
That makes a female who's had a certain, who's had a phalloplasty.
00:11:05.480
So there are traits that are associated with sex that are associated with the body plan to
00:11:15.180
And those traits vary, but sex is just one or the other and you're stuck with it forever.
00:11:25.300
Because I think as a society, we hear this term intersex and again, speaking for myself,
00:11:30.780
especially, um, I, I would entirely would have considered castor-seminia intersex and maybe
00:11:37.800
that's, you know, an umbrella term, but having you explain it in the way that you did to where
00:11:46.600
But it's really an underdeveloped penis that, that makes a lot of sense.
00:11:53.200
It's, it's the genital tubercle early in uterine development.
00:11:57.340
If exposed to testosterone, basically will develop into the penis.
00:12:01.880
If not exposed, it stays something that looks like the clitoris and it's, sorry, it's not
00:12:10.200
And what look like labia that all males and females have early in development, they're called
00:12:20.960
So scrotal sacs are like sort of elaborate, um, labia.
00:12:27.620
If you don't have DHT, you're stuck with the labia.
00:12:30.480
So you have, you end up with what is, you know, does have a vaginal opening.
00:12:37.120
Um, and I just want to say these DSDs, these people need medical care.
00:12:46.960
So, you know, it's hard to just talk about this as like, these people are pawns in this
00:12:51.320
game, but these are people who have these differences or in some cases disorders that
00:12:56.860
really are, you know, can be quite serious, um, medically and socially.
00:13:01.940
So we should treat these people with respect and compassion and dignity.
00:13:09.320
But for sports, it's a little bit like the transgender issue where you have to face biological reality.
00:13:18.000
And it can be unpleasant, uh, in, in many ways, but it's necessary if we want to have
00:13:23.140
fair sports to talk about the biological reality.
00:13:29.580
And so I guess my question for you, these guidelines that are being pushed by the International
00:13:35.980
Olympic Committee or the NCAA or the National Women's Soccer League, or these different sport
00:13:40.680
governing bodies, they have specific levels of testosterone, right?
00:13:45.040
And this is mumbo jumbo to a lot of people, including myself.
00:13:48.500
Um, when they were telling us, you know, men can, or I guess males can compete against women
00:13:53.240
if they've reduced their testosterone levels through HRT to a level of 10 nanomoles per liter,
00:13:58.040
for example, which was the guidelines for the IOC at the time.
00:14:02.360
Um, and I think it's still for the, for the Women's Soccer League.
00:14:04.880
And so my question for you, can you help us make sense of what these numbers mean?
00:14:09.200
Um, so what the average range of a, of a female's level of testosterone versus the average level
00:14:20.220
So I just want to say that these rules are predicated upon the idea that fair play could
00:14:29.360
potentially be achieved if males who transition to living as females by reducing their testosterone,
00:14:38.080
uh, if they reduce their testosterone, then that, that would mitigate the testosterone induced
00:14:44.340
advantages that are largely accumulated during puberty, right?
00:14:49.820
So that's when males really start to outperform females because of a testosterone, um, high
00:14:58.640
So the idea is that if they reduce testosterone, then the, it'll be an equal playing field or
00:15:09.260
Um, so, but then the regulations, the, the initial regulations were that males would have
00:15:15.180
to reduce their T levels to about 10 nanomals, um, per liter.
00:15:22.080
And the typical female range is actually only about 0.1 or 0.2 to around two nanomals per liter.
00:15:32.380
It is minuscule compared to what the range of males, which the lower end of that range is
00:15:42.340
So that is many times the upper range, the very upper range of the female level.
00:15:49.380
And then the high end for males is around 30 to 40, uh, nanograms per liter.
00:15:56.040
And that all depends on the eight, you know, age, uh, of each sex, because obviously it varies
00:16:05.720
Um, and I just want to say some people argue, and I think disingenuously, um, that there is
00:16:13.480
great overlap between the testosterone levels of males and females.
00:16:18.060
It, there's no overlap in healthy, uh, people who don't have like a sick testosterone secreting
00:16:26.840
tumor or who has, especially male athletes who dope, they can increase their testosterone
00:16:34.100
And then when they stop doping before a competition, they have gained all of the benefits from, uh,
00:16:41.920
training with artificially high testosterone levels.
00:16:44.960
Then they can, uh, stop doping so that when they take their drug test, they have relatively
00:16:51.720
They can even, even have levels in the female range because doping shuts down the axis in
00:16:57.440
your brain that controls testosterone production from your testes.
00:17:01.180
So there you might have some evidence of overlap in testosterone levels, not because females are
00:17:07.400
high, but because sort of too many males are in the female range.
00:17:11.880
And that's generally because of disorders or doping.
00:17:15.780
You have to be suspicious if you hear claims that there's overlap, uh, in the levels, but
00:17:21.160
the levels that were required of like 10 nanomoles per liter is ridiculous because first of all,
00:17:28.020
the males still retain their advantages, um, that they benefited from in puberty.
00:17:33.700
And they get to have many times the current level of testosterone, uh, many times more than
00:17:47.760
Any male who's gone through male puberty, if they shut down their testosterone to nothing,
00:17:54.840
they on average, you know, if they're an elite athlete will still retain an advantage over
00:18:06.380
So these, these levels, um, again, for the people who don't understand, if you're saying
00:18:10.760
10 nanomoles per liter, that's, that's 10 times essentially around or more or more often
00:18:25.120
We're not meant to understand those terms unless we've, we've done the training and the
00:18:34.200
Um, again, in my experience at the NCAA, the guidelines changed to where it's, it's merely
00:18:39.680
12 months of hormone replacement therapy for a male to be able to compete in the women's
00:18:47.040
I know you mentioned previously that there's no amount of HRT, but, but 12 months, what does
00:18:52.160
Um, I, I think that we can acknowledge it reduces performance a little bit, um, because
00:18:57.640
you are losing some of that, that, that muscle.
00:19:03.740
Um, and, and, and another question I guess I have is, is it dangerous for men to reduce
00:19:10.320
their testosterone levels when, when you are on average around somewhere within that 20,
00:19:14.800
30, 40 range for men, if you're asking men to get below five nanomoles per liters, is that
00:19:21.600
Um, so I'll just, I'm not sure we have time to answer the dangerous part, um, but I do
00:19:27.220
want to make clear that first of all, um, Emma Hilton and Tommy, Tommy Lumberg have done
00:19:35.040
a great, uh, review paper that shows very clearly all of the available evidence from, uh, research
00:19:43.880
that had been done previously on the effects of, uh, adult males suppressing testosterone
00:19:51.580
on the physical parameters that would affect sports performance, like muscle mass, strength,
00:20:05.020
So the idea would be that, first of all, I just want to say in male puberty, testosterone
00:20:11.440
goes up, you know, it could be 10 to even 40 times that of female levels.
00:20:17.540
And it causes the energy that we take in from food to be used to, um, develop muscle over
00:20:30.040
And so as an athlete, as a female athlete, you have to carry more dead weight where males
00:20:38.420
So there's an advantage right there in terms of lean body mass.
00:20:41.360
That's an, you know, for the same height and weight, if you have more lean body mass on
00:20:46.260
average, you go, you're going to, um, win at, you know, beat females in most sports.
00:20:54.540
And that's a large difference in lean body mass and strength.
00:20:58.860
And the, you know, upper body strength can be around 60% higher in males.
00:21:04.340
Like that's a massive advantage in many sports.
00:21:10.060
So it depends on the sport, you know, what particular trait is going to give somebody an
00:21:14.420
advantage, but there's a height advantage that is a testosterone mediated.
00:21:18.040
There is bone density advantage, testosterone mediated muscle mass, much greater muscle mass,
00:21:25.840
uh, grip strength, different sort of, uh, bone structure that can aid in throwing speed
00:21:33.420
and power, especially, uh, heart and lung volume.
00:21:40.820
Um, so spray strength, speed, and power, right?
00:21:48.000
And there is something like a muscle memory going on so that in adulthood, if you block testosterone,
00:21:55.360
you don't lose all of that muscle mass and suddenly put on female levels of fat.
00:22:01.100
What we have learned from all the research is that males who block testosterone in adulthood
00:22:06.660
lose in a year on average, 5% of their muscle and strength.
00:22:13.460
What does go down to female levels fairly quickly is hemoglobin.
00:22:16.780
And that does make a big difference in VO2 max, um, and power essentially and endurance.
00:22:24.080
And that's important, but it doesn't mitigate the 10 to, you know, 50% advantage that males
00:22:37.320
It will, uh, reduce the advantage, but it's not a fair playing field.
00:22:47.600
And you certainly don't lose the entire, uh, strength advantage and power advantage.
00:22:57.240
And it's just sort of obvious to pretty much everyone, I think.
00:23:03.580
Well, I can tell you from my own experience, you mentioned women feeling like they were carrying
00:23:11.060
When I swam, I felt like I was carrying dead weight.
00:23:19.660
We could talk about this forever merely just because I'm super interested.
00:23:23.380
Um, I think this is incredibly captivating and you did such an amazing job of explaining
00:23:28.260
And really we couldn't be more grateful for you and more importantly for your stance and
00:23:34.500
Um, and just very briefly plug your book one more time.
00:23:41.000
Um, and, and let us know where we can find you on social medias.
00:23:45.980
It's, um, there's a different cover in the UK and a different title, but it's basically,
00:23:51.120
um, T the story of testosterone, the hormone that dominates and divides us.
00:24:02.540
I'm on Instagram, carol.hooven and follow me on Instagram because I want to start posting
00:24:07.580
and maybe I'll be inspired if I get more followers.
00:24:12.580
I have a website that I need to update, uh, carolhooven.com and Carol Hooven is C-A-R-O-L-E-H-O-O-V-E-N.