Current evidence from a pooled analysis points to comparable physical fitness between transgender women and cisgender women after the first years of gender affirming hormone therapy. Researchers reviewed dozens of studies and thousands of participants to weigh body composition against real world measures such as upper and lower body strength and maximal oxygen consumption. The analysis finds higher lean mass in transgender women 1 to 3 years after hormone therapy, while measures used in routine fitness assessment show convergence with cisgender women. Method limits remain, including short follow ups, inconsistent reporting of training history, and scarce data on elite athletes. Policy debates on sport eligibility often refer to residual biological differences, yet pooled results from a large comparative study do not support blanket exclusion based purely on previous testosterone exposure. For coaches, sports medical staff, and policymakers, the evidence points to the need for nuanced, performance-specific rules built on rigorous exercise science and fair consideration of gender identity. This summary sets the stage for practical guidance and research priorities designed to balance inclusion, safety, and competitive integrity.
Physical fitness comparison: transgender women and cisgender women in pooled data
Meta-analysis of available studies contrasts body composition with functional tests. Across pooled data, transgender women show greater lean mass than cisgender women 1 to 3 years after hormone therapy, while aerobic and strength tests align closely between the groups.
Key finding: no observable differences in upper or lower body strength or VO2 max between transgender women and cisgender women in the studies pooled. This outcome challenges simple assumptions that lean mass alone predicts superior athletic performance. Insight: performance metrics matter more than isolated body composition numbers.
Study design and sample profile from the comparative study
Researchers included 52 studies with 6485 people overall. Participant breakdown: 2943 transgender women, 2309 transgender men, 568 cisgender women, and 665 cisgender men. Age range spanned from 14 to 41 years.
Most studies focused on adults. Only 16 studies used any physical activity assessment, and 7 studies adjusted for key confounders such as body composition, hormone levels, and nutrient intake. Insight: sample variety and limited adjustment restrict direct application to elite sport policies.
How hormone therapy affects body composition and functional fitness
Hormone therapy associates with higher fat mass and lower lean mass in transgender women within the first three years. Despite these shifts, functional outcomes used in routine testing show parity with cisgender women.
By contrast, transgender men demonstrate reduced fat, increased muscle, and greater strength after testosterone therapy. The comparative study highlights a divergence in body composition trends across gender transitions, but convergence in core physical fitness tests. Insight: hormonal effects on body composition do not automatically translate to permanent fitness advantage.
Limits on evidence and the elite athlete gap
Short study length and inconsistent reporting reduce certainty. Very few studies included elite athletes or sport-specific performance metrics. Muscle memory from prior training presents a plausible factor, yet data remain sparse.
Researchers call for long term, longitudinal studies prioritizing sport-specific outcomes and trained athlete cohorts. Practical takeaway: current evidence argues against blanket bans while urging targeted research to guide sport-level rules. Insight: policy requires both scientific rigor and sensitivity to athlete diversity.
Practical guidance for coaches, clinicians, and policymakers on athletic performance and gender identity
Coaches and clinicians must use objective fitness assessment and individualized planning when evaluating athletes. Policy makers must balance fairness, inclusion, and measurable health outcomes.
Use evidence to tailor selection and monitoring protocols. Avoid decisions based solely on past hormone exposure or unadjusted body composition figures. Insight: performance-based thresholds provide clearer, fairer criteria than blanket rules.
- Prioritize sport-specific performance tests, for example power, strength, and VO2 protocols relevant to the discipline.
- Record training history and baseline fitness before interpreting post-transition metrics.
- Adjust for nutrition and current body composition in any comparative assessment.
- Monitor athletes longitudinally rather than rely on single time point measures.
- Create pathways for research partnerships between federations and exercise science labs to study elite-level cases.
Insight: a structured, data driven approach reduces bias and improves athlete care.
Research, public health, and wider implications for exercise science
Findings shape future research priorities in exercise science and inform public health messaging on inclusion and safety. Robust studies must include diverse demographics, puberty suppression histories, and competitive levels.
For readers interested in broader fitness topics, material on training tools and immune health provides practical context. See articles on fitness workout gear and exercise and immunity for applied guidance. Insight: contextual resources help translate scientific findings into daily training plans.
Our opinion
Current pooled evidence shows functional performance of transgender women largely aligns with cisgender women on routine strength and aerobic tests within the first years after hormone therapy. Evidence quality remains variable and elite athlete data remain scarce. Policy makers and coaches should base decisions on sport-specific performance metrics, transparent monitoring, and ongoing research. Final insight: fairness and inclusion require rules guided by data, not assumptions about biological differences.