The Price of Running as a Woman: Sex Testing, DSD Regulations and Sporting Justice

Update: On 10 July 2025 the Grand Chamber of the European Court of Human Rights found that Switzerland had violated Ms Semenya’s right to a fair hearing. The eligibility rules have also changed since this paper was written.

Several of the most significant legal challenges in sport have concerned the right of an individual to compete at all. In this paper, written after the CAS decision in Caster Semenya’s case in May 2019, AM Sports Law & Management Co. examines how sport has policed the boundary of the female category, and at what cost to the athletes concerned.

A long history

Physical gender testing was introduced at the European Athletics Championships in 1966, and the IOC Medical Commission went on to test female athletes at the Olympic Games, through practices widely criticised as intrusive and discriminatory, until 2000. Athletes such as Ewa Kłobukowska and María José Martínez-Patiño were caught up in it, and India’s Santhi Soundarajan lost her 800m silver from the 2006 Asian Games after a gender test. From 2011, the focus shifted away from chromosomes and anatomy to androgen levels.

Dutee Chand v. AFI and IAAF

Dutee Chand, from a village in Odisha, challenged the IAAF’s Hyperandrogenism Regulations before CAS. She succeeded on two of her four grounds: the regulations discriminated on the basis of a natural physical characteristic, and the IAAF had not shown that they were necessary and proportionate. The panel held that the IAAF had not proved that hyperandrogenism gave an advantage greater than other genetic and biological variations, and suspended the regulations for two years pending further evidence. The suspension was later extended.

The DSD Regulations

In 2018 the IAAF replaced the Hyperandrogenism Regulations with its Eligibility Regulations for the Female Classification (Athletes with Differences of Sex Development). They apply to athletes with specified 46 XY DSDs, testosterone of 5 nmol/L or more and sufficient androgen sensitivity, competing internationally in restricted events from 400m to the mile. To compete, an athlete must be legally female or intersex, reduce her testosterone below 5 nmol/L for six months, usually with hormonal contraceptives, and keep it there, on a strict liability basis. Surgery is not required, and she may compete in other events, at national level, in the male category or in any intersex category.

The CAS decision

On 1 May 2019, by a majority, CAS dismissed the challenge brought by Caster Semenya and Athletics South Africa. The panel unanimously found the regulations discriminatory, but held that they were necessary, reasonable and proportionate to protect fair competition in women’s athletics, accepting that endogenous testosterone is the primary driver of the performance gap between men and women. It recorded concerns about the side effects of hormone treatment, the difficulty of keeping natural testosterone consistently below the limit, and the limited evidence for the 1500m and the mile.

Our view

The regulations apply only to women. No man is asked to lower his testosterone, and other biological advantages, from aerobic capacity to physique, are not regulated at all. Asking doctors to prescribe contraceptives for a purpose they were not intended to serve raises ethical questions for the medical profession, and the UN Human Rights Council described the regulations as “unnecessary, humiliating and harmful”. In our view the DSD Regulations are a lighter version of the hyperandrogenism rules they replaced. Sport is organised around a rigid line between male and female categories that biology does not always draw, and the athletes who fall on that line bear the consequences. Semenya asked only to run as the woman she is.