A recent study has found that trans women have comparable levels of physical fitness to their cisgender counterparts.

The Brazilian study, which was published in the British Journal of Medicine, analysed the body composition and physical fitness of a number of trans women before and after receiving gender-affirming hormone therapy.

The participants were assessed across a number of key criteria, including fat mass, lean mass, upper-body strength, lower-body strength, and the maximum rate at which the body consumes oxygen during exercise (VO₂ max).

Across the categories of fat mass, upper body strength, lower body strength and VO₂ max, researchers found “no significant differences were observed between transgender women and cisgender women”. While transgender women demonstrated a higher absolute lean mass when compared with cisgender women, there were no significant differences found in the relative lean mass grade.

In the study’s discussion section, the researchers state that transgender women “exhibit body composition distinct from both cisgender men and cisgender women”, with trans women possessing “significantly higher fat mass than cisgender men but levels comparable to cisgender women”.

The researchers continue: “Regarding lean mass, transgender women show values significantly higher than cisgender women but significantly lower than cisgender men. Of relevance, despite differences in lean mass, no significant differences were found in upper-body or lower-body strength between transgender women and cisgender women. In contrast, both upper-body and lower-body strength were markedly lower in transgender women compared with cisgender men.”

The study pointed to longitudinal analysis, which demonstrated that one to three years of hormone therapy in transgender women “leads to progressive increases in fat mass and concurrent declines in lean mass and upper-body strength”.

“The convergence of transgender women’s functional performance with cisgender women, particularly in strength and aerobic capacity, challenges assumptions about inherent athletic advantages derived solely from GAHT or residual lean mass differences,” the study stated.

This is not the first instance in which a study has disputed the popular talking point that trans women have a distinct physical advantage over cis women in sport. A 2024 study, for instance, found that athletic trans women, who had received gender-affirming hormonal care, had worse performance in lung function, jump height, and VO₂ max than cisgender women.