Men and women compete in most Olympic events separately. Until the 21st Century this was almost completely true, with the exception of some open events in equestrian, sailing, and shooting, and mixed events in badminton, figure skating, table tennis, and tennis. However, in recent years it has become de rigeur for men and women to compete in mandatory mixed team or relay events in multiple sports.
In addition, the situation in the 21st Century has become complicated by the transgender movement in which young people change the gender assigned to them at birth, which has been supported by the LGBQT+ movement. In a few cases these transgender people have been athletes who wished to compete in their new gender class, usually transgender women who had been assigned male at birth.
The two sexes compete separately in most events because of the physical advantage claimed by men. Men posing as women would have a significant competitive advantage over natural women. At the 1936 Olympics, Dora Ratjen of Germany finished fourth in the women’s high jump, but was later found (1938) to have been a man raised as a girl. There were several other similar examples in the 1930s, notably Czechoslovakia’s Ždenka Koubková, a woman who later had surgery to become a man, who competed in track & field events internationally, but never competed at the Olympics. The 1932 women’s 100 metre Olympic champion was Stanisława Walasiewicz of Poland. At her death in 1980, her autopsy revealed she had mixed sexual characteristics. Her original birth certificate was later examined and “she” was found to have been christened Stefania Walasiewicz.
In the 1960s, concern about this problem of men posing as women to gain a competitive advantage led to the introduction of gender verification, at the time called sex testing. At that time, several of the women track & field athletes were suspected of being genetically male. Sex testing began at the 1966 European Athletics Championships, and was first used at the Olympics in 1968. At the 1966 European Athletics Championships, Ewa Kłobukowska of Poland was disqualified from further international competition. Kłobukowska had won a gold and bronze medal at the 1964 Olympic Games. Because of the obvious emotional and psychological trauma engendered by such an announcement, all subsequent sex testing results have not been released publicly.
From 1968-88, all women wishing to compete in the Olympics were required to undergo sex testing. (With one exception, that being HRH Princess Anne of Great Britain, who competed in the 1976 Olympics in the equestrian events.). Testing was initially done by obtaining a buccal smear, or a scraping of the cells of the inner wall of the mouth. The cells were examined for the presence of a Barr body, which occurs almost exclusively in females. Females are genetically labeled as XX, while men are labeled as XY, those being the classifications of the respective sex chromosomes. The second X chromosome possessed by women contains a structure termed the Barr body.
Though some men did attempt to breach the rules and compete as women, the entire subject of mixed sexual characteristics is a highly complex and emotional one. A number of people with mixed sexual identity may have elected to compete as women for psychological reasons. In addition, doctors typically label babies with indeterminate genitalia as women. And in certain cases of mixed sex classification, some people who would be considered women lack a Barr body, and would thus have been disqualified. Because of these problems, the test was later changed and the buccal smear no longer used. Women were then cleared for international competition by doctors after simply undergoing a physical examination. In the late 1980s, this method was replaced by a polymerase chain reaction evaluation, looking. for the Y-linked SRY gene (sex-determining region Y), and this method was used at both the 1992 and 1996 Olympics.
But problems still existed. It was noted that the tests failed to exclude all potential impostors, and were discriminatory against women with disorders of sexual development, and could be psychologically devastating for a female athlete failing such a test. Thus, during the 1996 IOC World Conference on Women and Health, the International Olympic Committee (IOC) passed a resolution “to discontinue the current process of gender verification during the Olympic Games.” The IOC Athletes’ Commission recommended to the IOC Executive Board in January 1999 that gender identification should be eliminated, and this decision was ratified by the IOC Executive Board in June 1999.
However, the IOC Medical Commission addressed the issue of sex reassignment in 2003-2004. Their recommendations were approved by the IOC Executive Board in May 2004. The conclusions of this study were: 1) individuals undergoing sex reassignment of male to female before puberty should be regarded as girls and women (female); 2) individuals undergoing sex reassignment of female to male before puberty should be regarded as boys and men (male); 3) individuals undergoing sex reassignment from male to female after puberty (and vice versa) be eligible for participation in female or male competitions, respectively, under the following conditions: 3a) surgical anatomical changes have been completed, including external genitalia changes and gonadectomy; 3b) legal recognition of the assigned sex has been conferred by the appropriate official authorities; 3c) hormonal therapy appropriate for the assigned sex has been administered in a verifiable manner and for a sufficient length of time to minimize gender-related advantages in sport competitions; 3d) eligibility should begin no sooner than two years after gonadectomy; and 4) evaluation will occur on a confidential case-by-case basis.
The problem of gender in international sport again became prominent at the 2009 World Athletics Championships, when the women’s 800 metre event was won by South African Caster Semenya. Questions were raised about the athlete’s gender, and after the Championship, it was revealed that Athletics South Africa had performed gender verification tests on Semenya prior to the meet and had not released these results.
In 2015 further problems arose when Dutee Chand, an Indian sprinter, was found to have high levels of endogenous testosterone, and was not allowed to compete internationally at the Commonwealth Games. It was felt that her hyperandrogenism gave her an unfair advantage, and there were suggestions that if she wished to compete with women, she would need to take drugs, or have surgery, to lower her endogenous testosterone levels. In July 2015, the Court of Arbitration for Sport (CAS) ruled in Chand’s favor, stating that her hyperandrogenism did not defintively give her an unfair advantage over other woman and ruled that she should be able to compete in future international events against women.
At the Tokyo 2020 Olympics New Zealand weightlifter Laurel Hubbard competed as a woman. She had been born Gavin Hubbard but in 2012 underwent sex reassignment surgery and hormonal treatments after puberty, but this was still controversial because of the strength advantage gained by going thru male puberty. Hubbard was allowed to compete after showing that her testosterone levels were those usually seen in biologic females. She had been a silver medalist at the 2017 World Championships but failed to complete a valid snatch at Tokyo and did not finish.
At the Paris 2024 Olympics the situation received significant media attention because of two boxers whose precise gender classification was uncertain, but who also wished to compete as females. Algerian Imane Khelif competed in the women’s welterweight (60-66 kg) division and Lin Yu-Ting of Chinese Taipei competed in the women’s featherweight (54-57 kg) class. Both eventually won gold medals. In May 2025 World Boxing mandated gender verification testing for women’s categories and Khelif was no longer allowed to compete as a female. However, Lin underwent the gender verification test and in March 2026 was cleared by World Boxing to compete in the female class.
As the controversies related to transgender participation in female events became more common, many International Federations (IFs) began to address the issues and make regulations concerning who could compete as females. Because of the differences in sporting requirements these regulations often varied between the IFs.
In September 2025 IOC President Kirsty Coventry announced the formation of a new “Working Group on the Protection of the Female Category” whose charge was to specifically look at recent developments in transgender participation at the Olympic Games. The Working Group was created specifically to examine scientific, medical, and legal developments since 2021. The Working Group members came from five continents and included specialists in sports science, endocrinology, transgender medicine, sports medicine, women’s health, ethics, and law. Because of the sensitive nature concerning these controversies, the working group members’ names were not revealed.
In March 2026 the IOC and the Working Group announced the “Policy on the Protection of the Female (Women’s) Category in Olympic Sport and Guiding Considerations for International Federations and Sports Governing Bodies”. The full announcement and the background can be found at this link (link valid as of 27 March 2026).
In summary the final policy made the following decisions:
For all disciplines on the Sports Programme of an IOC Event, including individual and team sports, eligibility for any Female Category is limited to Biological Females.
Eligibility for the Female Category is to be determined in the first instance by SRY Gene screening to detect the absence or presence of the SRY Gene, considered a marker for male sexual development.
Except for athletes with a diagnosis of complete androgen insensitivity syndrome (CAIS) or other rare disorders of sexual development that do not benefit from the anabolic and/or performance-enhancing effects of testosterone, no athlete with an SRY-positive screen is eligible for competition in the Female Category.
Athletes with an SRY-positive screen, including XY transgender and androgen-sensitive XY-DSD athletes, continue to be included in all other classifications for which they qualify, for example, they are eligible for (i) any Male Category, including in a designated Male slot within any mixed category, and (ii) any open category or in sports and events that do not classify athletes by Sex.
The Policy was to be applied to all IOC Events and entered into force at the date of its adoption by the IOC Executive Board. It was not retroactive and shall be applicable for the first time at the LA28 Olympic Games.
This Policy shall be adopted by IFs and other sports governing bodies, such as National Olympic Committees (“NOCs”), National Federations and Continental Associations (“SGBs”), when exercising their responsibility in implementing eligibility rules in relation to IOC Events.
