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Right to compete: Transgender women

Over the past few years, voices have proclaimed that allowing transgender women to compete in women’s sports creates an intolerable unfairness. It is certainly true that on average transgender women are taller, bigger and stronger than cisgender women and that these differences are advantageous in many sports. If, however, one looks beyond the obvious size differences between trans and cis women, one sees a substantially different picture.


All women deserve to have a sporting category in which they can enjoy meaningful competition, and this necessitates eligibility requirements for the female category. Many international sports governing bodies have decided to limit the testosterone levels of trans women. In order to track the effectiveness of this policy it would be prudent to look at what happens to the performance of trans women who undergo testosterone suppression.

The hormone therapy that trans women undergo is designed to make their bodies more like cisgender women; it generally induces typical female testosterone and oestrogen levels. Let’s see what happened to the performance of two prominent trans athletes as they underwent hormone therapy.


Yanelle Zape is a Colombian sprinter who ran 10.7 seconds for 100 meters prior to undergoing hormone therapy and could only run 12.5 seconds for the distance in 2016 after being on hormone therapy. Part of Zape’s reduction in speed was due to aging, but once one factors in the aging component, Zape is sprinting at approximately the same level as a woman as she did as a man. Zape is currently competing at a high level in master’s athletics.


Hannah Mouncey is an Australian handball player who has competed for both the men’s and women’s national teams in international tournaments. Mouncey lost over 20 kilograms of muscle once she went on hormone therapy, but her residual size of 1.88 meters and 100 kilograms still makes her an outlier in the women’s game. Despite her size and strength advantages, Mouncey was only the 3rd leading scorer for the Aussie women’s side which placed fifth out of ten teams in the 2018 Asian handball championships. Although Mouncey was one of the more effective players on the national squad, she was not invited to join the team for the 2019 World championships where the Aussies placed 24th and last.


Beyond looking at individual trans athletes, it would be useful to examine some population statistics. The most appropriate cohort to examine would be collegiate sports in the United States. Every year more than 200,000 women participate in NCAA sports and the organization has allowed transgender women to compete after one year of hormone therapy since 2011. Given that trans people probably comprise between 0.5 and 1.0% of the population, equal representation would entail approximately 1500 trans women competing in the NCAA every year. There are probably fewer than 50 trans women currently competing in the American collegiate system. Hence, nine years after the implementation of hormone-based rules, trans women are still hugely under-represented in NCAA sports.


Performance analysis of transgender athletes is still in its infancy, but over the next several years a small group of international scientists are committed to examining transgender athletes as they undergo hormone therapy. The resulting data will be very important to sporting organizations around the world, and will hopefully result in updated regulations regarding transgender athletes. Unless and until such data indicate a better means to determine eligibility for women’s sport, hormone-based regulations offer the best method of ensuring that all women have the opportunity to engage in meaningful competition with their peers. Any suggestion that transgender women are on the verge of taking over women’s sport is misguided, disingenuous, and bigoted.


Joanna Harper is a doctoral researcher at Loughborough University who has published papers on transgender athletic performance and served as an advisor to multiple international sports governing bodies including the IOC.

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