The International Olympic Committee (IOC) recently made an announcement that signalled a decisive shift in how elite sport addresses male advantage and eligibility for participation in women’s sport categories. The newly announced policy will be applicable for all athletes who wish to be eligible to compete in women’s categories starting with LA Olympics 2028.
The implications are significant: the IOC is now explicitly acknowledging that biological sex is paramount and the advantages conferred by male puberty must be effectively countered. After years of frameworks that leaned heavily toward inclusion, the IOC is now moving toward a position that better reflects scientific evidence and prioritises fairness, safety and integrity of women’s sport.
This piece is an attempt to explain the import of this announcement, how we got here, what is at stake, and why this landmark decision deserves support.
1. What has the IOC actually announced?
The recent announcement is an explicit position to anchor eligibility in women’s sport to biological sex rather than identity-based or purely hormonal criteria.
An element of the new policy is the use of genetic sex screening, including markers such as the SRY gene, as a more objective basis for classification of sex. The SRY gene, located on the Y chromosome, is closely associated with male sex development. A one-time screening for SRY will from now be mandatory for eligibility to compete in women’s categories at the Olympics. This sits alongside a broader move away from earlier IOC frameworks that relied primarily on testosterone thresholds. The IOC now recognises that male advantage is multi-factorial and persists beyond hormone levels, and that eligibility rules must reflect this reality.
Importantly, the IOC has set clear guiding principles—fairness, safety, and integrity of competition— enabling sport-specific federations to define how these are implemented.
2. Why is this shift significant?
Because it aligns policy more closely with biology. Male puberty leads to increases in muscle mass, strength, cardiovascular capacity, and skeletal structure—advantages that are both substantial and durable. Even after testosterone suppression, many of these attributes remain outside the typical female range.
This matters because sport is, at its core, a system designed to neutralise advantage where it is overwhelming. If the category itself cannot do that, competition ceases to be meaningful. The IOC’s shift is therefore less a policy tweak and more a reaffirmation of why women’s sport exists as a separate category.
3. What brought us here?
The debate did not emerge overnight. It has been shaped by a series of high-profile cases and policy experiments. The case of Caster Semenya was a pivotal moment. Her challenge to testosterone regulations, ultimately upheld by the Court of Arbitration for Sport, forced World Athletics, and to a larger extent, society, to confront the tension between inclusion and fairness in female sport.
Subsequent policies, particularly the IOC’s 2015 guidelines, leaned toward inclusion via hormone thresholds. Over time, however, evidence accumulated that these measures were insufficient. More recent controversies, including debates around athletes such as Imane Khelif during the Paris Olympic cycle, further highlighted how unclear or inconsistent rules can erode trust in competition.
Together, these moments exposed the limits of earlier frameworks and pushed governing bodies toward a more evidence-based position.
4. What is the core issue this addresses?
At stake is the integrity of women’s sport, which rests on three interlinked principles: fairness, safety, and credibility.
Fairness requires that female athletes are not systematically disadvantaged by competitors who have gone through male puberty. Safety becomes particularly relevant in contact sports, where physical disparities can translate into real risk. Integrity, meanwhile, speaks to whether results are perceived as legitimate—an essential condition for any sport to retain meaning.
If these principles are compromised, the category itself is undermined.
5. What does science say about “male advantage”?
The performance gap between males and females is one of the most robust findings in sports science. While hormone therapy can possibly reduce some variables, it does not fully reverse advantages in speed, strength, size, or power. These retained benefits are precisely what sport categories are designed to account for. At elite levels, the difference between standing on the podium and missing out (not just on medals, but also all the associated financial and other consequences) is predicated on the thinnest of margins.
The male/female performance gap ranges from a 10-15% advantage in sports that primarily require speed & power in movement (athletics, swimming, cycling, etc ) all the way up to 40-80% in sports that reward strength & force (boxing, wrestling, etc). Crucially, this gap is not driven by testosterone alone, but by a constellation of physiological changes triggered during male puberty.
6. Where does SRY screening fit into this?
The discussion around the SRY gene—linked to male sex development—reflects an attempt to anchor eligibility in objective biological markers rather than subjective or variable criteria. While scientifically grounded, such approaches are not without complexity, particularly in cases involving a condition known as Complete Androgen Insensitivity Syndrome (CAIS) . The IOC has acknowledged this in the announcement and has proposed ways to deal with this.
But the broader direction is clearly evident: sport is seeking clearer, more defensible ways to define categories based on biology.
7. What are the main objections to the announcement?
Critics argue that stricter eligibility rules risk excluding transgender women and may conflict with principles of inclusion and identity recognition. Concerns are also raised about the mental health impact of exclusion, as well as the fact that biological variation exists within all categories, including among women.
These considerations deserve to be engaged respectfully with arguments based on established science, with the underlying anchor in the above mentioned principle of protecting fairness, safety and integrity in female sport.
8. Why must sex, not gender, define eligibility in sport?
Sport ultimately measures physical performance, and the largest, most consistent performance divide is between biological males and females. Gender identity, while socially and personally significant, does not alter the physiological effects of male puberty. Using gender as the basis for categorisation therefore fails to address the very asymmetry that women’s sport was created to manage.
“Sex is a biological construct, gender is a social construct”
The key point is that sport is not a general social space—it is a structured system built on classification. Categories based on sex, weight, age, and disability already exist, not as statements of worth, but as mechanisms to ensure meaningful competition.
In this context, inclusion cannot be absolute if it erodes the very purpose of the category. The rights of transgender athletes are real and important, but so too are the rights of female athletes to compete on fair terms. Balancing these requires acknowledging that not all forms of inclusion are compatible within a single category.
9. What does this mean going forward?
The IOC’s current stance signals a gradual but clear shift toward science-led, sport-specific policies that recognise the reality of male advantage. While the debate will continue, the direction is toward greater clarity, not less.
For women’s sport, this is ultimately about preservation. Not preservation in a defensive sense, but in ensuring that the category continues to offer what it was designed to: a fair, safe, and meaningful arena for female athletes to compete and excel.
Exploring alternative formats—such as open categories—may be one way forward without compromising fairness. Case in point - the World Major marathon events now have a non-binary category – this should be the norm across all sports.
Closing
At its best, sport is one of the clearest expressions of merit—where effort, talent, and preparation meet on terms that are understood to be fair. That clarity does not happen by accident; it is carefully constructed through categories that exist precisely to ensure that outcomes are meaningful.
The IOC’s recent direction is, in that sense, not a departure but a return—to first principles. It recognises that women’s sport exists because biological differences matter, and that ignoring those differences, however well-intentioned, ultimately undermines the very athletes the category was created to serve.
None of this diminishes the importance of inclusion, dignity, or respect for all individuals. But sport has always required boundaries, and not all boundaries are unjust. Some are essential. The task is not to erase them, but to define them honestly.
If women’s sport is to remain a space where female athletes can compete, excel, and be recognised on fair terms, then those boundaries must be grounded in biological reality, not abstraction. The IOC’s shift acknowledges this with greater clarity than before.
And in doing so, it takes an important step toward ensuring that the future of women’s sport remains not only inclusive in spirit, but credible in competition and uncompromised in purpose.
PS:
Resources: For readers who want to get into more depth into this complex and nuanced issue, it will be useful to follow the work of sports scientist Ross Tucker via his Real Science of Sport podcast and other writings, to get a comprehensive and expert understanding of this sensitive issue.
Satish took to running in his 40s and believes that it has been the most transformative experience of his life. Over the last 15 years, he has run many marathons/HMs/10Ks and ultras like Comrades. Satish is a passionate advocate of running as a lifetime activity. He mentors other runners as his way of giving back to this beautiful sport that has filled his life with joy and meaning.