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

"I'm tired of hearing about money, money, money, money, money. I just want to play the game." — Shaquille O'Neal

Caster Semenya is a South African middle-distance runner. She won gold at the 800m in Rio. She was born a woman, raised as a woman, and identifies as a woman. Under the IAAF's current Differences of Sex Development (DSD) Regulations, she cannot compete in her signature events as a woman unless she takes medication to suppress her natural testosterone levels. If that sounds preposterous, consider: her only other options are to compete against men, or to stop competing altogether.

This is the question at the heart of one of sport's most controversial legal disputes — and the answer, I would argue, reveals a deeper tension between the IAAF's drive for categorical certainty and the messy, inconclusive reality of human biology.

A Brief History of Sex Testing in Sport

Gender testing in sport began at the European Athletics Championships in 1966 with the IOC's infamous "gender parade" — women athletes made to parade naked before a Medical Commission. This continued until 2000, when it was rightly condemned as discriminatory and intrusive. The subsequent move to hormone-level testing, specifically androgen levels, was presented as more scientific. It was not necessarily more just.

India has its own painful chapter in this history. Santhi Soundarajan, who won silver at the Doha Asian Games in the women's 800 metres, failed a gender test and had her medal stripped. She suffers from Androgen Insensitivity Syndrome. The difference between how India treated Soundarajan and how South Africa stood behind Semenya is worth reflecting on.

The Dutee Chand Case: A Partial Victory

The legal history begins meaningfully with Indian sprinter Dutee Chand's challenge at the Court of Arbitration for Sport (CAS) against the IAAF's Hyperandrogenism Regulations. Chand's challenges were fourfold: discrimination on the basis of a natural physical characteristic, flawed scientific assumptions, lack of proportionality, and an allegation that the regulations amounted to an unauthorised doping sanction.

CAS upheld Chand on discrimination and proportionality. The IAAF had not provided sufficient evidence that hyperandrogenism conferred a significant advantage over other genetic or biological factors — no greater than the advantages conferred by superior nutrition, specialist training, or other genetic variations. The regulations were suspended for two years pending further evidence. It was a landmark ruling, but a temporary one.

Semenya v IAAF: A Different Outcome

The IAAF used the Dutee Chand window to gather further evidence and replace the Hyperandrogenism Regulations with the DSD Regulations in 2018. The new regulations targeted a narrower set of athletes — those with 46 XY DSD and testosterone levels of 5 nmol/L or above — and required them to reduce testosterone to compete in eight restricted events including the 400m, 800m and 1500m.

By a majority, CAS upheld the DSD Regulations. The panel acknowledged unanimously that the regulations are discriminatory — they target a subset of female athletes on the basis of immutable biological characteristics. But the majority found that elevated testosterone in 46 XY DSD athletes conferred a significant performance advantage, and that the DSD Regulations were a proportionate response because they allowed athletes to continue competing without surgical intervention, relying instead on oral contraceptives.

The UN Human Rights Council described the DSD Regulations as "unnecessary, humiliating and harmful." The International Medical Association flagged ethical concerns about prescribing oral contraceptives for purposes they were not designed for.

What the Law Cannot Resolve

The deepest problem with the DSD Regulations is not legal — it is epistemological. Sport has constructed a binary (male/female) and biology has refused to honour it. No man is asked to compete with women because of low testosterone. No man is asked to reduce his levels because they are too high. The asymmetry is stark: women's victories come with conditions attached that men's victories do not.

Sports science experts have also questioned whether the evidence demonstrates that higher testosterone offers an advantage meaningfully greater than longer legs, larger lung capacity, or better access to training. The science remains genuinely contested — which makes a rule that forces irreversible medical intervention on the basis of contested science particularly difficult to defend.

Conclusion

Caster Semenya and Dutee Chand have revealed what has always been true: sport's insistence on drawing a clean line between male and female categories produces cruelty at the margins where no clean line exists. The DSD Regulations offer one kind of certainty — categorical certainty — at the cost of bodily autonomy for a small number of athletes whose only offence is being physiologically unusual. That is not a trade-off that can be justified on the face of existing evidence alone. The law has spoken. Whether sport has acted justly is a different question entirely.