Are transgender women allowed to compete in the Olympic Games?

The IOC leaves this to the individual sports federations. Some federations allow participation under certain hormone conditions; others exclude transgender women who have gone through male puberty from the women's category.

Do transgender women always have a sporting advantage?

This is scientifically not unambiguous. In recreational sport the differences are generally minimal. In elite sport, some physiological characteristics remain present longer after hormone therapy, but the extent differs per sport and person.

How does the Dutch sports world deal with transgender athletes?

NOC*NSF has drawn up guidelines for sports clubs. The emphasis is on inclusion in recreational sport and on policy development in consultation with international federations for elite sport.

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Gender and sport

Sports competitions have historically been divided into two categories — men and women — for one simple reason: the body that has been through male puberty is in most athletic domains significantly stronger, faster and larger than the body that has been through female puberty. The women's category does not exist out of politeness, but because fair competition and the health of female athletes otherwise cannot be guaranteed. The question of whether transgender women — biological men who identify as women — may compete in the women's category goes directly to this foundation.

Male puberty: a physiological legacy that lasts

The advantages produced by male puberty are far-reaching and largely permanent. Under the influence of testosterone in puberty, men on average develop:

considerably more muscle mass and muscle strength (in the order of 30–50% in the upper body);
larger bones, a larger skeletal size and higher bone density;
greater heart and lung capacity;
a more favourable lever structure (longer limbs, narrower hips);
a higher haemoglobin level and thus higher oxygen transport capacity.

One or two years of oestrogen therapy — as required by some sports federations — does not reverse these changes. Skeleton, heart size and lever ratios are permanent. Muscle mass and strength do decrease somewhat, but studies (including Hilton & Lundberg, 2021; Roberts et al., 2021) show that a considerable part of the strength difference relative to women remains even after several years of hormone treatment.

Unfair competition

Admitting transgender women to the women's category in practice means that biological men — often with a lifelong legacy of male puberty — compete against women. In disciplines where strength, speed and motor power are decisive (athletics, swimming, cycling, weightlifting, MMA, rugby) this demonstrably leads to performance advantages. For female elite athletes this means a loss of podium places, scholarships, record attempts and selection spots. That is not an abstract problem but a direct undermining of the women's category itself.

Injury risk for women

Alongside fairness, safety also plays a role. In contact and collision sports — rugby, football, judo, MMA — greater mass, more strength and higher bone density in biological men lead to a demonstrably higher injury risk for female opponents. In 2020 World Rugby, on the basis of its own research, concluded that admitting transgender women to the women's category increases the risk of serious injury by tens of percent. Similar considerations apply in other collision sports.

Policy of international sports federations

Under pressure from scientific evidence and female athletes, several international federations have adjusted their policy. Since 2023 World Athletics and World Aquatics exclude transgender women who have been through male puberty from the women's elite. UCI (cycling), World Rugby and USA Powerlifting follow comparable lines. The IOC leaves the choice to individual federations, but the call for unconditional inclusion the IOC previously made has in practice been overtaken.

Intersex athletes

A separate discussion concerns intersex athletes with a DSD condition (Differences of Sex Development) who were raised as women but have XY chromosomes and endogenous testosterone levels in the male range (for example 46,XY 5-alpha-reductase deficiency). Well-known cases such as Caster Semenya show that these athletes in practical terms have the same physiological advantages as other biological men. Sports federations have — rightly — drawn up eligibility rules for this. This is not a "transgender" discussion, but a biological sex discussion. See also Intersex.

Recreational sport

In recreational sport performance and injury risk play a smaller role in most cases. Many clubs opt for pragmatic local solutions. This does not, however, relieve top-level and competitive sport of the duty to protect the women's category as a sex category, precisely because national and international titles, prize money and careers are at stake there.

What is at stake?

The women's category in sport is the achievement of decades of women's emancipation. It is based on biological sex, not on a feeling. Fully abolishing or hollowing it out in the name of inclusion in practice means excluding women from their own category. That is too high a price — and more and more sports federations, athletes and scientists are concluding the same.

Do the advantages of male puberty disappear after a year of hormones?

Is excluding transgender women from the women's category discrimination?

What is the position of the Dutch sports world?