Ross Tucker

Sports scientist, PhD Exercise Physiology. The Science of Sport podcast. Not on here much these days. Find me at

[Ross Tucker @Scienceofsport]

I want to try to explain something about testosterone and performance, since it has become the ‘fixation’ and the ‘the fix’ for inclusion policies for both DSD and trans athletes. So here’s a thread to ‘debunk’ and explain why T level, per se, is not quite the right place to look

[Ross Tucker @Scienceofsport]

@BonitasMomToo @foundlost421 @Reikern @BrianTruckin As for that original contention, it's laughable by any standard of reality. Strength differences are 30-50%, power differences 30%, speed is 12-15% greater in men. Even elite trained women have strength similar to that of the average untrained man, as shown in studies

[Ross Tucker @Scienceofsport]

@BonitasMomToo @foundlost421 @Reikern @BrianTruckin Closer, but by no means equal! At the marathon, it's 10%, and then it stays there pretty much up to the longest running and cycling events we do. Check the WRs for 24 hour (12%), 100km (9.4%), and so on. Even there, male advantage is large and real

[Eric Rawson, Ph.D. 🎅🏻 @EricRawsonPhD]

Honored to be a guest on the Real Science of Sport Podcast to talk all things creatine. Thanks to to Mike and Ross for great discussion! @Scienceofsport

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[Ross Tucker @Scienceofsport]

The Peptide Show. Our latest podcast explores peptides - the hype, the politics, the fascinating origin-stories & legitimate concerns, and why the reward is inseparable from risk, while science chases marketing. From GLP1s to BPC-157, we have you covered: https://t.co/mslpkgcbFe

[Ross Tucker @Scienceofsport]

@olenoerskov @runthinkwrite @TimHutchings1 I had the same thought watching it. I was thinking Werro needs to throw her elbows out and defend that space, or she is inviting problems. I can’t believe this got as controversial as it did. It was clearly correct to advance Werro. Patriotic confounder maybe.

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan Also, wrong question. Male. Why? Because identity is not relevant to the performance. So you need to compare males to Biles, not a subset of males, who are biologically the same, but who identify differently.

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan They don't, really,have you seen what the top male gymnasts do in the disciplines or apparatus that they have in common? You might need to revist this theory, if this is your agument for absence of male advnatage.

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan And we really do have 100% clarity on this. If we did not, then you would be able to offer me examples of females at a given weight, X, who are equal to males at X. Or tall women, 1.88m or 6ft2 tall, like Brunson, in the NBA. But you can't. Because sex matters. So try again.

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan They're not. Sport is literally structured that way. Unless you have found a cohort of people who play basketball in height categories, or combat sport without weight categories. Or, make a case for those, rather than a sex boundary that we should ignore on the basis of self ID

[Ross Tucker @Scienceofsport]

@HJoyceGender I'm at the point now where I don't believe anyone is this gullible unless they are literally begging to make fools of themselves for the sake of their choices! The alternative feels almost more depressing to me! (almost!!

[Ross Tucker @Scienceofsport]

@HJoyceGender Choices. As it has been for years now, as we've discussed, and I know you know. There was a point, I think years ago now, where people's (and sports') opinions & actions on this were a clear indication of the choices they made DESPITE what they knew, and what the facts were.

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan It was your point that physical differences are unfair. I'm saying the opposite, which is that WITHIN a category, physical differences determine the result and hence get rewarded and praised. But sex differences are not these. Otherwise, we'd have ONE champion per event & sport

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan I really am not. I've heard your point a hundred times in the last few years, it's hardly new. Physical differences are the thing sport actually WANTS to reward. The physical differences that arise because some humans are male, and others are female, are NOT the ones we value.

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan What circumstances, spell it out, and interrogate it. If the sport has any benefit as a result of strength, power, mass, speed, or endurance, then male advantage makes it unfair, because some humans have access to biology others never will. It's why the category exists.

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan And by the way, the Knicks were led to success by a MALE, in the men's category, who, at 6ft2, or 1.88m is in the top percentile of height among men. He is, legit, a very tall male. Not average at all. So he hardly makes the case for "large spread of humans who can succeed".

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan ...a category is created for females, and you allow males into it? So let's make this real simple - should women's sport exist? If yes, why? is it identity, or biology? If biology, then what would allow males to be equal to females? What's the minimum requirement from biology?

[Ross Tucker @Scienceofsport]

@ijbailey That's not true, no. The false positive rate was basically zero. What they did with them is the issue you'd take issue with. The biology suggests they were correctly identified. It leaves us with choices as to what advantage we allow in women's sport. Male, or not?

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan even if identity leads someone to reduce T levels. Every metric (with the exception of hemoglobin) that we have and is measured - biological or performance related - shows that T reduction only removes a small % of the original Male advantage. So on what basis is equality crated

[Ross Tucker @Scienceofsport]

@ijbailey @piersmorgan Because Self ID does not change the biology. You can identify as you wish, your cells, and their response to male hormones, does not know this. So males, regardless of identity, are males. So research that compares male to female does not concern itself with identity.