IOC restores sex testing for the 2028 female category as the evidence stays contested

The International Olympic Committee decided on 27 March 2026 that eligibility for female events at the Olympic Games will be limited to athletes who do not carry the SRY gene, with the rule taking effect from the Los Angeles Games in 2028. Verification is a one time test taken from saliva, a cheek swab or a blood sample. The IOC's stated reasoning, as reported by the ABC on 27 March 2026, is that "the presence of the SRY gene is fixed throughout life and represents highly accurate evidence that an athlete has experienced male sex development". IOC president Kirsty Coventry said the policy was "foundationally based in science and led by medical experts", and that it would not be fair for "biological males to compete in the female category".

The Olympic body is following athletics rather than leading it. World Athletics announced on 30 July 2025 that its Council had approved eligibility regulations requiring a once in a lifetime SRY test, effective 1 September 2025 and in force for the world championships that began in Tokyo on 13 September 2025. Its president Sebastian Coe said that "gender cannot trump biology". The consultation material behind that decision put the pre-pubertal performance gap in athletics at three to five per cent in running events and higher in throwing and jumping, and its working group concluded that testosterone suppression could only ever partly mitigate male advantage.

The largest recent synthesis of the physiology points the other way, and its authors are careful about how far it goes. A systematic review with meta-analysis led from the University of Sao Paulo was published in the British Journal of Sports Medicine on 11 February 2026, covering 52 studies and 6,485 participants. It reported that transgender women had similar relative lean mass to cisgender women (standardised mean difference 0.19, 95 per cent confidence interval -0.14 to 0.53), similar lower body strength (0.05, -1.31 to 1.40) and similar maximal oxygen consumption (-0.28, -0.81 to 0.25). The authors concluded that the evidence "does not support theories of inherent athletic advantages for transgender women over cisgender" women. They also graded most of those comparisons as low or very low certainty under the GRADE system, and the pooled studies are largely of non elite populations. Regulators and their critics can each find something in that.

A separate objection is that the test does not measure the thing the rule is about. Writing in The Conversation on 10 June 2026, Ari Berkowitz of the University of Oklahoma argued that the presence of SRY is not the same as having benefited from androgens, and that a screen of this kind will catch women with partial androgen insensitivity, women with 5-alpha-reductase deficiency and women with genetic mosaicism, none of whom necessarily gain a performance benefit. He also noted that fewer than ten transgender athletes were competing among roughly 510,000 United States college athletes, and that one transgender woman is known to have competed in Olympic women's events since 1900.

Opposition was organised before the decision landed. On 17 March 2026 the Sport and Rights Alliance, ILGA World and Humans of Sport published a statement signed by more than 160 organisations, arguing that the IOC abandoned universal sex testing after 1996 precisely because it was an inaccurate test of both sex and athletic advantage. The statement said mandatory screening exposes women and girls to scrutiny and humiliation, creates safeguarding risks by requiring young women's and children's bodies to be investigated, and falls hardest on women from the global south who already face barriers. It put the cost of sex verification at upwards of 10,000 United States dollars per athlete once follow up investigation is counted.

The Australian Olympic Committee endorsed the change on the day it was announced. Its president Ian Chesterman said the rule gives female athletes fairness and certainty before 2028. Chef de mission Anna Meares said she also knew "the pain this decision will cause some athletes and I empathise with them". Paula Gerber, a law academic at Monash University, told the ABC that mandatory testing contravenes international human rights covenants and that binary definitions of this kind reinforce harmful stereotypes. The advocacy group Pride Cup said the policy would make all women targets for harassment and abuse and could breach Australian anti-discrimination law. Kimberly Frost of ILGA World asked, of the protective framing, "How is this protection?"

What is not yet known is substantial. No full expert review or membership list for the group that advised the IOC could be located and opened for this article, so the weight the committee gave to the Sao Paulo meta-analysis cannot be checked against its own record. It is not clear who pays for testing, what confirmatory process follows a positive result, how those results will be stored and protected, or whether national federations will mirror the rule below elite level. Nor is it settled whether the low certainty of the current evidence reflects a genuine absence of advantage or simply an absence of studies of elite athletes, which is the question the rule turns on and the one the published science does not yet answer.