4. Caster Semenya
South African middle-distance runner Caster Semenya’s eligibility has sparked global debates on gender and fairness in athletics. Born with differences in sex development (DSD), Semenya’s body naturally produces higher levels of testosterone than most women. This led to the introduction of regulations by World Athletics requiring female athletes with DSDs to lower their testosterone levels to compete in certain events. Semenya challenged these rules, arguing they violated her human rights. In July 2025, the European Court of Human Rights ruled in her favor, stating that Switzerland had not provided sufficient safeguards in reviewing her case. This decision highlighted the ongoing tension between inclusion and classification in sports. For more insights, see The Guardian.