A new study out of the U.K. undercuts the idea that transgender women have an advantage over cisgender women in sports — and suggests that trans women are less like cis men than many suppose.

The study was funded by the International Olympic Committee and conducted at the University of Brighton in England. It was published in April in the British Journal of Sports Medicine.

The participants consisted of 23 trans women, 21 cis women, 19 cis men, and 12 trans men. They all were involved in competitive sports, although not at the national or international level, or did physical training at least three times a week. All the trans women had been on medication to suppress testosterone for at least a year and were taking estrogen.

Trans women in the study had greater handgrip strength than cis women, but they had lesser jumping ability than both cis women and cis men, plus lower lung function and cardiovascular fitness than cis women.

“While longitudinal transitioning studies of transgender athletes are urgently needed, these results should caution against precautionary bans and sport eligibility exclusions that are not based on sport-specific (or sport-relevant) research,” the study concluded.

A key takeaway is that “trans women are not biological men,” Yannis Pitsiladis, one of the authors, told The New York Times.

Some have criticized the study, claiming it was influenced by the IOC and that it deliberately used trans women who were less physically fit than cis men. But the authors emphasized that all participants met the same criteria for physical activity, and Pitsiladis told the Times that IOC officials did not pressure researchers regarding the outcome.

The IOC lets the governing body for each sport determine whether trans athletes can compete. The National Collegiate Athletic Association has a similar policy.The National Association of Intercollegiate Athletics, which represents small colleges and universities, has barred transgender women from participating in women’s sports. Twenty-five states have laws or policies restricting trans students’ participation in public school sports, with some of the laws also applying to colleges and universities and, to some degree, to private schools.

Pitsiladis said he and his team have been threatened over the study. That could have a chilling effect on research, he told the Times. “Why would any scientist do this if you’re going to get totally slammed and character-assassinated?” he said. “This is no longer a science matter. Unfortunately, it’s become a political matter.”

Anna Baeth, director of research with Athlete Ally, which works for LGBTQ+ inclusion in sports, welcomed the study. “The science is murky when it comes to specific hormones like testosterone and trans women athletes — primarily because no study, until this one, have examined trained athletes who identify as transgender,” Baeth told Forbes. “What does remain clear is that there are hundreds of factors that impact athletic performance, especially social ones. If governing bodies are serious about creating better and more opportunities for women, their focus should be on the numerous, proven research which consistently finds unequal treatment of women’s sports in participation opportunities, funding and resources, access to facilities and infrastructure, and media coverage.”