Transgender Women Show No Athletic Advantage Over Cisgender Women After Hormone Therapy

Debates around transgender athletes in competitive sports often center on whether gender-affirming hormone therapy fully eliminates physiological differences that could confer athletic advantages. This systematic review and meta-analysis provides the most comprehensive evidence to date on how body composition and physical fitness compare between transgender and cisgender individuals.

Researchers from the University of São Paulo searched PubMed, Web of Science, Embase, and SportDiscus, ultimately including 52 studies with 6,485 participants. Outcomes assessed included relative fat mass, relative lean mass, upper- and lower-body strength, and maximal oxygen consumption (VO2max). Studies examined both pre-to-post GAHT changes and direct comparisons with cisgender controls.

For transgender women, no statistically significant differences were found compared to cisgender women in fat mass, lean mass, upper- or lower-body strength, or VO2max. GAHT over one to three years was associated with increased fat mass and reductions in lean mass and upper-body strength in transgender women. Transgender men showed higher fat mass and lower lean mass and upper-body strength than cisgender men, with GAHT producing the opposite trajectory — reduced fat and increased lean mass and strength.

The findings suggest that while transgender women may retain slightly higher lean mass than cisgender women at a population level, their measurable physical fitness does not differ significantly. The authors conclude that current evidence does not support theories of inherent athletic advantage for transgender women over cisgender women.

Critically, the evidence quality is mostly rated very low to moderate by GRADE standards, and significant heterogeneity exists across studies. More rigorous, longitudinal research is needed before firm policy conclusions can be drawn.