A unique pseudo-eligibility analysis of longitudinal laboratory performance data from a transgender female competitive cyclist

The Union Cycliste Internationale has deemed transgender female athlete’s ineligible for the female category due to concerns about performance advantages. We conducted a follow-up analysis on laboratory-based performance indicators of sports performance using data from a longitudinally assessed transgender woman athlete undergoing gender-affirming hormone therapy (GAHT). We evaluated laboratory performance indicators in transgender and cisgender women athletes using dual-energy X-ray absorptiometry scanning, handgrip strength measurement, jump testing, and cardiopulmonary exercise. Additionally, we assessed a transgender sub-elite cyclist before and after undergoing GAHT. After one year of GAHT, the transgender athlete showed declines in handgrip strength (7–13 %), countermovement jump (23–29 %), and V̇O2max (15–30 %). After 3 months, several performance indicators (absolute handgrip, peak power, relative peak power, average power, relative average power, V̇O2max and relative V̇O2max) were above the mean of cisgender female athletes, while others (Relative handgrip, countermovement jump and relative countermovement jump) were below. Similar trends were observed at 6 months and 1 year. This hypothetical analysis, although with limited evidence, suggests the transgender athlete could compete equitably in elite cycling events within the female category after one year of GAHT. Adjustments based on competition data would ensure fairness. Further analysis after an additional 12 months is recommended to assess the impact of 2 years of GAHT. An outright ineligibility for the female category for transgender women athletes would hinder a true assessment of performance fairness.