A new study funded by the International Olympic Committee found that transgender athletes showed greater grip strength (an indicator of overall muscle strength), but lower jumping ability, lung function and relative cardiovascular fitness compared to women whose gender was assigned at birth.
That data, which also compared trans women to men, contradicted a broad claim often made by advocates of rules barring transgender women from competing in women’s sports. It also led the study’s authors to warn against a rush to expand such policies, which already exclude transgender athletes from a handful of Olympic sports.
The most important finding of the study, according to one of its authors, Yannis Pitsiladis, member of the IOC medical and scientific commission, was that, given the physiological differences, “trans women are not biological men.”
Alternately praised and criticized, the study added an intriguing set of data to a volatile and often politicized debate that is perhaps only getting louder with the Paris Olympics and the US presidential election approaching.
The authors cautioned against presumpting immutable and disproportionate advantages for transgender athletes competing in women’s sports, and advised against “preemptive bans and exclusions from sports eligibility” that were not based on sport-specific research.
However, absolute prohibitions continue to proliferate. Twenty-five U.S. states now have laws or regulations banning transgender athletes from competing in women’s and girls’ sports, according to the Movement Advancement Project, a nonprofit organization that focuses on gay, lesbian, bisexual and transgender parity. . And the National Association of Intercollegiate Athletics, the governing body for smaller universities, this month banned transgender athletes from competing in women’s sports unless they were assigned the female sex at birth and have not undergone hormone therapy.
Two of the most visible sports at this summer’s Paris Games – swimming and track and field – along with cycling, have effectively excluded transgender athletes who went through puberty as men. Rugby has instituted an outright ban on trans athletes, citing safety concerns, and those allowed to participate in other sports often face stricter requirements to suppress their testosterone levels.
The International Olympic Committee has left eligibility rules for transgender athletes up to the global federations that govern individual sports. And although the Olympic committee provided funding for the study (as it does on a variety of topics through a research fund), Olympic officials had no input or influence on the results, Dr. Pitsiladis said.
Generally, the argument in favor of the bans has been that the profound advantages gained from testosterone-driven male puberty (broader shoulders, larger hands, longer torsos, and greater muscle mass, strength, bone density, and cardiac and cardiac capacity) pulmonary) give transgender athletes an unequal and largely irreversible competitive advantage.
The new IOC-funded, peer-reviewed laboratory study at the University of Brighton, published this month in the British Journal of Sports Medicine, tested 19 cisgender men (those whose gender identity matches their assigned sex). birth) and 12 trans men, along with 23 trans women and 21 cisgender women.
All participants played competitive sports or performed physical training at least three times a week. And all of the trans athletes had undergone at least a year of treatment to suppress their testosterone levels and take estrogen supplements, the researchers said. None of the participants were athletes who competed at a national or international level.
The study found that transgender women showed greater grip strength than cisgender women, but lower lung function and relative VO2 max, the amount of oxygen used when exercising. Transgender athletes also scored lower than cisgender women and men on a jump test that measured lower-body power.
The study acknowledged some limitations, including the small sample size and the fact that the athletes were not followed long-term during their transition. And, as previous research has indicated, transgender athletes were found to retain at least one advantage over cisgender athletes: a measure of hand grip strength.
But it’s a combination of factors, not a single parameter, that determines athletic performance, said Dr. Pitsiladis, professor of sports and exercise sciences.
Athletes who grow larger and heavier after going through puberty as men must “carry this big skeleton with a smaller engine” after the transition, he said. He cited volleyball as an example and said that for transgender athletes, “jumping and blocking will not be at the same level as before. And they may find that they perform less well overall.”
But Michael J. Joyner, a Mayo Clinic doctor who studies the physiology of male and female athletes, said that based on his and others’ research, science supports bans in elite sports, where events can be decided by the smallest of margins.
“We know that testosterone improves performance,” Dr. Joyner said. “And we know that testosterone has residual effects.” Furthermore, he added, trans women’s decreased performance after taking drugs to suppress their testosterone levels does not completely reduce the typical differences in athletic performance between men and women.
Supporters of transgender athletes and some scientists who disagree with the bans have accused governing bodies and lawmakers of implementing solutions to a problem that doesn’t exist. There are few elite trans athletes, they have observed. And there have been limited scientific studies on the supposedly unalterable advantages in strength, power, and aerobic capacity gained by experiencing puberty as a man.
For those who have competed in the Olympic Games, the results have varied greatly. At the 2021 Tokyo Games, Quinn, a non-binary trans soccer player assigned female at birth, helped Team Canada win a gold medal. But Laurel Hubbard, a transgender weightlifter from New Zealand, failed to complete a lift in her event.
“The idea that trans women are going to take over women’s sports is ridiculous,” said Joanna Harper, a prominent trans athlete researcher and postdoctoral fellow at Oregon Health and Science University.
Dr. Harper, who is transgender, said it was important for sports to consider the physiological differences between transgender and cisgender women and that she supported certain restrictions, such as requiring the suppression of testosterone levels. But she called the blanket bans “unnecessary and unjustified” and said she welcomed the IOC-funded study.
“This fear that trans women aren’t really women, that they are men invading women’s sports and that trans women are bringing all of their male athleticism, their athletic abilities, to women’s sports, none of those things are true. “Dr. Harper said.
Sebastian Coe, president of World Athletics, which governs global athletics, acknowledged that the science remains unresolved. But the organization decided to exclude transgender athletes from international athletics, he said, because “I’m not going to take any risks with this.”
“We think this is the best thing to preserve the women’s category,” Coe said.
In at least two high-profile cases, the fight over transgender bans has moved to the courts. Former University of Pennsylvania swimmer Lia Thomas is challenging a ban imposed by World Aquatics, swimming’s world governing body, after winning the 500-yard freestyle race at the 2022 NCAA championships. Thomas, who had been among the Ivy League’s top male swimmers, became the first known trans athlete to win a women’s championship in the top division of college sports.
However, Thomas did not dominate all of her races, finishing tied for fifth in a second race and eighth in a third. Her winning time in the 500 meters was more than nine seconds slower than the NCAA record. Her case, brought before the Switzerland-based Court of Arbitration for Sport, is not expected to be resolved before the Paris Olympics begin in July.
Meanwhile, more than a dozen current and former American college athletes, including at least one who competed against Thomas, sued the NCAA last month. They claimed that by allowing Thomas to participate in the national championships, the organization had violated his rights under Title IX, the law that prohibits sex discrimination at institutions that receive federal funds. (Title IX has also been invoked to defend transgender athletes.)
Outsports, a website that reports on LGBTQ issues, hailed the IOC-funded study as a “landmark” that concluded that “blanket sports bans are a mistake.” But some scientists and athletes called the study deeply flawed in an article in The Telegraph, which called the suggestion that transgender women are disadvantaged in sports a “new low” for the IOC.
The debate is so heated that Dr. Pitsiladis said he and his research team have received threats. That, he warned, could lead other scientists to avoid further research on the topic.
“Why would a scientist do this if they are going to completely criticize and murder you?” he said. “This is no longer a scientific question. Unfortunately, it has become a political issue.”