South African Olympic gold medalist Caster Semenya lost an appeal Wednesday in athletics' highest court, which ruled that restricting testosterone levels in runners with "differences of sex development" is discriminatory but should be done anyway.
The Court of Arbitration for Sport (CAS) sided in favor of the International Association of Athletics Federations (IAAF) rule to regulate testosterone levels, meaning some athletes, such as Semenya, may need to take medication to suppress their testosterone levels in order to compete at international races.
The IAAF argued that the female runners with high testosterone levels have an unfair advantage in races ranging from 400 meters to 1 mile.