A recent study financed by the International Olympic Committee (IOC) has brought forward a new data set to the ongoing and often hotly debated discussion about trans women and their place in elite sports.
The research showed that transgender female athletes had greater handgrip strength—an indicator of overall muscle strength—but lower jumping ability, lung function and relative cardiovascular fitness compared to cisgender women.
The data contradicts the general sentiment that transgender female athletes have a distinct, irreversible advantage over cisgender women which has led to numerous sports federations barring them from competing in women’s sports.
The study was conducted at the University of Brighton (UK) and published this month in the British Journal of Sports Medicine. It tested 19 cisgender men and 12 trans men, along with 23 trans women and 21 cisgender women, all of whom either played sports competitively or underwent physical training at least three times per week. All of the transgender female athletes had undergone at least one year of testosterone suppression and estrogen supplementation.
The findings included:
- Transgender female athletes showed greater handgrip strength compared to cisgender females
- Transgender female athletes had lower lung function and relative VO2 to cisgender females
- Transgender female athletes scored lower than cisgender females and men on a jumping test that measured lower-body power
The study acknowledged its limitations, including a small sample size and not following the athletes over the long term while they transitioned.
One of the study’s authors, Yannis Pitsiladis, told The New York Times that the most important finding was that given physiological differences, “Trans women are not biological men.”
Although the study showed trans female athletes had greater handgrip strength, Dr. Pitsiladis said it is a combination of factors that determined athletic performance.
Athletes who grow taller and heavier after going through male puberty must “carry this big skeleton with a smaller engine” after transitioning, said Dr. Pitsiladis, who is also a member of the IOC’s medical and scientific commission.
Citing volleyball as an example, Dr. Pitsiladis said that for trans female athletes, “the jumping and blocking will not be to the same height as they were doing before. And they may find that, overall, their performance is less good.”
However, Mayo Clinic Doctor Michael J. Joyner, who studies the physiology of female and male athletes, said that the science supports the various bans on trans female athletes from competing in women’s sports.
“We know testosterone is performance enhancing,” Dr. Joyner said, according to The New York Times. “And we know testosterone has residual effects.”
Dr. Joyner added that declines in performance by trans women after taking hormone-suppressing drugs don’t fully recplicate the typical differences in athletic performance between men and women.
According to the Movement Advancement Project, 25 U.S. states have laws or regulations barring transgender athletes from competing in girls and women’s sports, while some of the sports that will have the most eyes on them at this summer’s Olympics, including swimming, have effectively barred transgender female athletes from competing in the female category.
The IOC, which financed the study but had no input or influence on the results, left eligibility rules for trans women’s participation up to global sports federations.
World Aquatics published its criteria for competing in men’s and women’s divisions in March 2023 and declared intentions to create a new ‘open’ category for trans athletes, which debuted at the Berlin World Cup last year and had no entries.
World Athletics president Sebastian Coe acknowledged that the science surrounding trans athletes is unresolved, but the global governing body barred transgender female athletes, with Coe saying he wasn’t “going to take a risk on this.”
On April 8, the National Association of Intercollegiate Athletics (NAIA) announced a new policy banning trans women from competing in women’s sports.
Arguably the most prominent case of trans women in sports is former Penn swimmer Lia Thomas, a trans woman who won the 2022 NCAA title in the women’s 500 freestyle. ‘
Thomas is challenging World Aquatics current sanction on trans women, while just last month, a group of 16 current and former female athletes, including multiple who competed against Thomas, sued the NCAA over its transgender policy.
Dr. Pitsiladis said he and his researchers have received threats since publishing the study. And with that reality and the political nature of the topic, it will likely lead other scientists to turn away from pursuing the topic further.
“Why would any scientist do this if you’re going to get totally slammed and character-assassinated?” he said, according to The New York Times. “This is no longer a science matter. Unfortunately, it’s become a political matter.”
I would like to see more studies comparing real-world results of trans women (and men) in sports competitions. Instead of studies with obvious weaknesses in terms of number and comparability of study participants.
Are trans women more successful in women’s competitions than they were previously in men’s competitions? Do they achieve higher rankings? Are trans men just as successful in men’s competitions or are there differences?
This should give you an indication of whether or not trans women have an advantage over cis women. It would be interesting to look at the results of trans men in particular – because according to the proponents of inclusivity, transitioning is supposed to eliminate pre-existing physical differences. This must then also apply to trans… Read more »
This is valuable research despite all the well-described limitations. Regardless of exactly where you stand on this issue, I’d argue that it really matters quite a bit exactly how much and in what ways trans women differ in athletic abilities than cis women. It’s not just as simple as a binary question of “is there any difference”… it matters how much of a difference!
As many people have said, sports are not remotely fair already. Height, socioeconomic status, and so many other factors dictate ability beyond one’s sex.To specifically nitpick around the axis of gender+sex on the basis of fairness is much more justified if the differences between trans and cis athletes are huge, but it becomes harder to defend… Read more »
This whole issue is ridiculous. Just change it from Men’s and Women’s swimming divisions to Open and Female swimming divisions…. No cis dude is going to care if a trans women wants to race them. It’s obviously unfair for females to have to compete against a trans-women.
Sounds like a study wherein the testing was orchestrated so that the “test results” would match the desired results.
yes, it was widely ridiculed not just in the last couple of weeks since publication, but since many months before that when the lead researcher was recruiting participants with an ad that appealed to *trans women who feel it’s unfair they’re banned from female categories* — come and show how weak you are!
Read the study- and pay close attention to the paragraph “Study Limitations”. It’s a very weak trial and doesn’t answer any key or relevant questions. Too few subjects, not enough centers participating (inherent bias)…in other words, very low power. It’s a complex area of study, and, while this trial attempts to elucidate differences, it just creates more questions (which need to be understood by better study designs) than answers. Not a personal attack on the investigators btw, but just being forthright with what this study is and more importantly, what it is not (definitive or imperial science).
Lia vs Liam is the case study that is hard to ignore. Liam went 4:18 in the 500 freestyler. Lia went 4:33 in the 500 freestyle. 4:18 is an incredibly fast time. How many men in the world (high school, age group, NCAA, foreign junior and senior swimmers, etc.) can go 4:18? Maybe 500? 1000? You would certainly be the top one tenth of 1 percent of all male swimmers. How many women can go 4:33?
it’s the 100, though, that’s illustrative. Liam went 47, Lia went 47. Liam’s 47 was half-decent at a high school meet. Lia’s got into a final against the some of the fastest women on the planet.
Furthermore, Lia’s sprint freestyle technique was horrid. Awful underwaters, terrible breathing pattern, poor breakout off the start & the stroke itself wasn’t good. No way someone with technique that poor is hanging with the best in the world without substantial biomechanical/physiological advantage.
You really think someone going a 4:18 in the 500 can only go a 47 in the 100? Almost certainly Liam never swam a tapered 100 so we don’t know what his time should have been. There’s valid points to be made but this one is obviously bad.
85 men went 4:18 or faster this year in the NCAA. 3 women went 4:33 or faster this year in the NCAA. Pretty clear Lia is the superior athlete when compared to Liam respectively.
This doesn’t seem to really answer anything we didn’t already know. Comparing “competitive athletes” to those who train “three times a week” just isn’t comparable too. They acknowledged they didn’t look at results over the course of the transition, and that’s kind of the only part of this discussion that matters.
If a man who was at the 80th percentile in performance of his sport transitions, will he then be in the 80th percentile among women? If yes, okay great no real advantage. If he’s relatively better among women though, then there’s a competitive advantage. This study doesn’t come close to answering that.
I recently talked to an expert from the University of Stuttgart at a panel on inclusion in Darmstadt. The subject of the panel was more about disabled kids, but I took the opportunity to talk to him about transgender athletes as well. He was also a swimmer if that’s relevant. He did say that pretty much anything concerning the inclusion of transgender people was still in its infancy and that it’s important to listen to what they need. And that the vast majority of transgender kids (not adults) he talks to, are mostly concerned with having safe spaces to be who they are and that, despite his general attitude that everyone can be included in anything if we are just… Read more »
Thanks for sharing that convo! A lot of good points to consider.