After 2 years of hormones, trans women still ran 1.5 miles 90 seconds faster

What this chart asks

Does a year or two of hormone treatment close the running gap between transgender women and women?

Why it is shown this way

• A line across the time bands shows whether the gap closes with treatment; the zero line is the average woman.
• The shaded band is the paper's 95% confidence interval, which is wide at 2-2.5 years because few women had reached that point.
• Seconds over the test distance are used because they are the paper's own unit and need no conversion.

Chart annotations

These markers provide relevant context for interpreting the chart. Their timing or position does not, by itself, establish causation.

Average Air Force woman under 30 (14:15)

Threshold: 0

Why this is marked: Zero is the comparison group in the study's Table 4; the 14:15 time is implied by the table.

Data and accessibility

Download chart data · Open accessible table · Download PNG · Download SVG

Dataset testosterone-suppression-athletic-measures, analysis air-force-run-gap

Sources

This chart draws on the sources of the dataset versions it visualizes.

Transgender women on hormones: what changes in a year, and Air Force fitness tests over 2.5 years

1. Harper J, O'Donnell E, Sorouri Khorashad B, McDermott H, Witcomb GL (British Journal of Sports Medicine) Systematic review, Tables 2-5: per-study changes in lean body mass, muscle cross-sectional area, strength and hemoglobin or hematocrit, with each study's testosterone before and after treatment, in transgender women on hormones. Free copy

   Retrieved November 5, 2026. CC BY 4.0. Open access under CC BY 4.0; FactHub republishes the extracted numbers with attribution.

   Reliability: Peer-reviewed study. Peer-reviewed systematic review of 24 studies of non-athletic transgender women, from Loughborough University and partners; no specific funding and no competing interests declared.

2. Roberts TA, Smalley J, Ahrendt D (British Journal of Sports Medicine) Table 4: U.S. Air Force fitness-test push-ups, sit-ups and 1.5-mile run times of 46 transgender women before and during hormone treatment, compared with the average Air Force woman and man under 30.

   Retrieved November 5, 2026. Copyright BMJ; numbers reported as facts. FactHub republishes the table's means, differences and confidence intervals as facts, with attribution; the article text is not redistributed.

   Reliability: Peer-reviewed study. Peer-reviewed study of U.S. Air Force medical and fitness records, 2004-2018, by military and academic pediatricians; no specific grant. Fitness tests measure endurance, not maximal strength, and the comparison is to an Air Force average, not matched controls.

3. Scharff M, Wiepjes CM, Klaver M, Schreiner T, T'Sjoen G, den Heijer M (Endocrine Connections) Cross-check of the largest 12-month study group: 249 transgender women in the European ENIGI cohort, grip strength 41.8 kg before and 40.0 kg after 1 year; median testosterone 17.9-18.5 nmol/L before and 0.4-0.8 nmol/L during treatment by clinic (Table 1). Free copy

   Retrieved November 5, 2026. CC BY 4.0. Open access; numbers republished with attribution.

   Reliability: Peer-reviewed study. Multicenter prospective clinical cohort in Amsterdam, Ghent and Oslo; authors declare no conflict of interest.

4. Wiik A, Lundberg TR, et al. (Journal of Clinical Endocrinology & Metabolism) Cross-check of the Wiik study group: thigh muscle volume fell 5% and quadriceps cross-sectional area 4% in 11 transgender women after 12 months, while strength was maintained.

   Retrieved November 5, 2026. Copyright Endocrine Society; numbers reported as facts. Numbers republished as facts with attribution.

   Reliability: Peer-reviewed study. Prospective study of 11 untrained transgender women at Karolinska Institutet, Stockholm; funded by Stockholm County Council and two foundations; no conflicts declared.

Limitations

• 46 Air Force members, not competitive athletes; the comparison is the Air Force average for women under 30, not matched controls.
• Few women reached 2-2.5 years, so that estimate is uncertain (10 to 169 seconds).
• In the same study, push-up and sit-up advantages were no longer statistically significant after 2 years; only the run advantage remained.
• Adults who went through male puberty; results may differ for people treated early in puberty.