The Study
The Impact of Gender-Affirming Hormone Therapy on Physical Performance
This study is like a summary of other studies, not a new experiment. It tells us what has been seen in trans people on hormone therapy, but it can't prove that the hormones caused the changes because there were no control groups or random assignments.
Analysis score
Maximum 5 for a narrative review.
Where the score came from
This study looks at how hormone treatments change strength and fitness in trans men and women who don’t play sports. It checks if their bodies get stronger or weaker over time and compares them to cis men and women.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 51 / 100
Quality score
Based on clinical experience or non-systematic literature reviews. The lowest level of evidence as they are most susceptible to bias and personal perspective.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The changes are big enough to close most fitness gaps, but trans women keep a small upper-body strength edge even after years of treatment.
- 2Trans men gain about 10% more muscle and 18% stronger grip in 1 year.
- 3By 3 years, their push-ups, sit-ups, and running match cis men.
- 4Trans women gain 30% more fat and lose 5% muscle in 1 year.
- 5After 2 years, their running is the same as cis women.
- 6After 4 years, sit-ups are the same, but they still do more push-ups than cis women.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of Clinical Endocrinology and Metabolism
Year
2023
Authors
A. Cheung, S. Zwickl, Kirsti Miller, B. Nolan, A. Wong, Patrice Jones, N. Eynon
Related Content
Claims (6)
Trans women on hormone therapy perform just as well—or just as poorly—as cis women in sports, with no real difference between them.
Trans women on long-term hormone therapy might have similar oxygen levels and fitness as cis women, even after going through male puberty.
Trans women who aren't athletes seem to run about as well as cis women after two years on hormone therapy — their endurance might become similar during that time.
Trans guys who aren't athletes gain noticeable muscle and strength in their first year on testosterone, and after about 3 years, their push-ups, sit-ups, and running get close to or match the average fitness levels of cis men.
Trans women who aren't athletes and take feminizing hormones tend to gain fat and lose muscle in the first year, with muscle continuing to decrease over three years, leading to a more typically feminine body shape.
Even after years of hormone therapy, transgender women might still be able to do more push-ups than cisgender women on average, possibly because some strength differences stick around longer than expected.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.