New BMJ Article on Trans-Athletes

[ThisZippyBlueCat]

Body composition and physical fitness in transgender versus cisgender individuals: a systematic review with meta-analysis.

"Conclusion: While transgender women exhibited higher lean mass than cisgender women, their physical fitness was comparable. Current evidence is mostly low certainty and has heterogenous quality but does not support theories of inherent athletic advantages for transgender women over cisgender."

Mendes Sieczkowska S, Caruso Mazzolani B, Reis Coimbra D, et al. Body composition and physical fitness in transgender versus cisgender individuals: a systematic review with meta-analysis British Journal of Sports Medicine Published Online First: 03 February 2026. doi: 10.1136/bjsports-2025-110239

https://bjsm.bmj.com/content/early/2026/01/22/bjsports-2025-110239

I had a feeling that when she was explaining how she got started on (then) Twitter it was something to do with an interest in beetles, possibly related to her developmental biology work. But I haven't been able to substantiate that with a quick Google so it is entirely possible it was a fever dream!

Who isn't fond of beetles? My favourite is probably Coleoptera elixa subsp. tunnockyvorans

You may well be right.

I think I remember her explaining about the quote at one stage. But it's also possible that was my own fever dream :)

No, you are absolutely right! From 2022:

"This is your regular reminder that I am not an entomologist and I do not study beetles.

My handle is derived from a quote about creationism and I research human genetics and genetic disorders, including one that kills males."

She then goes on to set out all manner of cool beetle types that she does not study, complete with pictures of each. Evidently my brain had retained the pretty pictures and multiple tweets about cool beetles but filtered out the "not" (such is the human my brain!)

Agreed. Her take down of the study on Twitterx is pretty comprehensive

Thank you for finding that!

Although the Tunnocks-eating beetle referred to above looks fair set to feature in a dream some time.

I always thought Scarabaeinae were fun and rather appropriate for this study.

The casual erudition on this board is a beautiful thing to behold (by which I refer to the highbrow allusion to Tunnocks teacakes as opposed to the lowbrow Latin declensions, obviously.)

This is what I was going to ask. I'm don't know anything about the professional science world or how it works, but here in the US scientific and medical institutions are under attack - especially by RFK Jr. and our Trump's department of health. But garbage like this gives the anti-science / anti-medical crowd real fodder that is hard to argue with. Can any yokle just conduct any "research" they want and legit journals will publish is as long as they provide a disclaimer? Is there no vetting? Standards? Accountability? Like seriously, how did this piece of trash get published can someone explain?

Have come across this on GBNews (sorry, only other place I have seen it). It doesn't matter what the article says, men should not be in women's sports because men in general have larger hearts and lungs, longer muscles and bones and much faster reactions, so much better explosive speed. None of that is affected by taking cross-sex hormones.

I'm fully prepared for someone to come along and critique my Latin, my only knowledge of Latin and Greek comes from seeing many Linnean binomials as part of my work. I was thinking about going with Crocs wearing but couldn't get hat to work at all.

In the context of this study being trans is something of a red herring. I'm fairly certain the reason why this group of transwomen's athletic performance is in any way more comparable to women, is because they have taken cross sex hormones and possibly surgeries. That is the important variable. Being trans is not relevant because any man can declare themselves trans and it will not change their body.

The real question being raised, is whether it is acceptable to allow men who have modified their bodies through drugs and/or surgery to be allowed to compete in women's sports. Which gets us into some unpleasant ethical dilemmas.

It is a form of doping, but instead of doping to excel in the correct sex category it is doping to excel in the incorrect sex category.

It is a form of reverse doping.

Deliberately suppressing performance with drugs and surgery. However, the crux of the issue really is,

What is the difference between a male person who has lost their ability to produce testosterone through disease or injury (or both) and is taking estrogen for medical reasons, and any male person doing this by choice to suit their identity?

There is none.

Except 'belief' and 'belief' alone.

It has been a purely philosophical based decision in the first place. Leveraged on the back of male people with DSDs who activists decided were being dehumanised by having to be tested with all the rest of the female people seeking access to the female sport categories. That was the mechanism that was used.

I suspect, in seeing the same names of activist academics on papers, that it could be reasonably argued that there could have been a staged strategy all along. First get those with DSDs accepted, then quickly pivot to male people who wanted to be included for gender identity.

Thank you, that is an important insight and reframing of the real question.

A slight addition:

Is it acceptable to allow men who have modified their bodies through drugs and/or surgery to be less performant than male norms to be allowed to compete in women's sports?

To be crystal clear, I was very much joking about your Latin declension being lowbrow. I too have very limited and specific knowledge of Latin and had to Google to get the joke!

I maintain that Tunnocks are the height of sophistication, however.

I wouldn't joke about that.

The Results section from the abstract:
52 studies (n=6485) were included. Transgender women had similar relative fat mass (standardised mean difference (SMD) −0.33, 95% CI −0.72 to 0.05, Grading of Recommendations Assessment, Development and Evaluation (GRADE): very low), relative lean mass (SMD 0.19, 95% CI −0.14 to 0.53, GRADE: low), upper-body strength (SMD 0.54, 95% CI −0.95 to 2.02, GRADE: very low), lower-body strength (SMD 0.05, 95% CI −1.31 to 1.40, GRADE: very low) and maximal oxygen consumption (SMD −0.28, 95% CI −0.81 to 0.25, GRADE: very low) in comparison to cisgender women. Transgender men exhibited higher relative fat mass (SMD 0.96, 95% CI 0.28 to 1.64, GRADE: moderate), lower relative lean mass (SMD −6.42, 95% CI −12.26 to −0.58, GRADE: moderate) and lower upper-body strength (SMD −1.46, 95% CI −2.52 to −0.40, GRADE: moderate) than cisgender men. In transgender women, GAHT was associated with increased fat mass and reduced lean mass and upper-body strength over 1–3 years. Transgender men demonstrated reduced fat mass and increased lean mass and strength following GAHT.

All those "(GRADE): very low" bits they are putting after the results mean that even in their own opinion, the quality of the evidence they have is very low. It's absurd anyone would look at this paper as a convincing and given it is only looking at composition of lean body mass, etc. is very biased in its attempt to make the conclusion sound like there is no good scientific evidence for the inherent athletic ability of transwomen over women.

So, they are basically ignoring all the physiological advantages males have over females when going through puberty.

Not quite - they adjust for them.

You mean like that ludicrous tennis match in Dubai at the end of last year between a man and a woman, Aryna Sabalenka and Nick Kyrgios?

Where the woman's side of the court was reduced by 9% and both players were restricted to a single serve per point to neutralize the man's powerful, high-speed serve.

Which Kyrgios won 6-3, 6-3 despite Sabalenka being the world number 1 female player and the fact that Kyrgios at the time was recovering from injury and is number 1283 in the men's world ranking.

You mean that kind of thing?

Strange that, because at no time in Khelif's fights did I see him with his hand tied behing his back. At no time when Caster Semenya was competing, did I see the women runners have a 100m start.

I hadn’t heard of that, but I meant in this study - they compared women to trans identified men after adjusting the men’s measurements to take account of things which impact performance like height. Hence ‘relative lean muscle’ not just ‘lean muscle’. In other words if you adjust the measurements to rule out male advantage you will find no male advantage….

But if you do what this study did - which in your example would be equivalent to discounting every time they won a medal and only presenting on ‘relative wins’, then they didn’t win…..

She really needs to stop being so ambivalent and speak her mind more clearly…

She doesn't mess around.