South African 800m runner Caster Semenya has hinted she may quit athletics, after losing her appeal against regulations restricting testosterone levels in female runners.
On Thursday (NZT), the Court of Arbitration for Sport admitted regulations restricting testosterone levels forfemale athletes in selected events were "discriminatory" but "necessary".
As a result, two-time Olympic 800m champion Semenya will have to take testosterone-suppressing medication.
Semenya put out two cryptic Twitter messages before her scheduled appearance at the Doha Diamond League, which will be the last race she can contest without medication.
Her first tweet read: "Knowing when to walk away is wisdom. Being able to is courage. Walking away with your head held high is dignity."
Following an outcry from upset supporters, Semenya posted another tweet that read: "That's me and will always be. I'm finished."
Semenya was added to the 800m start list in Doha on Friday, after she was initially left off while awaiting her appeal decision.
The 28-year-old has 30 days to appeal the decision made by the Court of Arbitration for Sport.