The Caster Semenya controversy revolves around the South African middle-distance runner's eligibility to compete in women's events. Semenya, who has naturally high levels of testosterone, has faced scrutiny and legal battles over regulations set by the International Association of Athletics Federations (IAAF). These rules require female athletes with elevated testosterone to lower their levels to compete in certain events. In 2019, the IAAF implemented new guidelines that specifically targeted athletes like Semenya, leading to widespread debate about gender, fairness, and the rights of athletes. Supporters argue that the regulations are necessary for a level playing field, while critics claim they discriminate against athletes with intersex variations.