If Caster Semenya wants to compete in certain women's Olympic and world championship events, the South African track star will have to start undergoing hormone replacement therapy or otherwise find a way to lower her hormone levels, per new rules from the International Association of Athletics Federations. CNN reports that the IAAF revealed Thursday that athletes with a new DSD (Difference of Sexual Development) designation—meaning they're hyperandrogenous, or have elevated blood testosterone levels—will need to lower those levels to an accepted number, then keep it that way.
The BBC notes Semenya, who has been asked previously to take a gender test, is likely to be affected by the new rules, which start Nov. 1 and apply to women competing in races ranging from 400 meters to 1 mile. "The revised rules are not about cheating … they are about leveling the playing field to ensure fair and meaningful competition," said IAAF President Sebastian Coe. If hyperandrogenous women don't lower their testosterone levels to meet the new standards, they'll be allowed to compete against men in international events. Semenya's most recent tweet, posted Thursday: "I am 97% sure you don't like me, but I'm 100% sure I don't care."