Caster Semenya Loses Case Seeking to Stop IAAF from Forcing Her to Reduce Her Testosterone Levels

South African middle-distance runner Caster Semenya has lost a landmark case where she was challenging International Association of Athletics Federations (IAAF) rules seeking to force female athletes to reduce their testosterone levels.

In a ruling on Wednesday, the Court of Arbitration for Sport (CAS) has rejected Semenya's challenge against the IAAF's new rules.

However, the CAS says it has "serious concerns as to the future practical application of the regulations."

In response to the ruling, the 800 meters Olympic champion says she knew the IAAF was specifically targeting her with the new rules.

"For a decade the IAAF has tried to slow me down, but this has actually made me stronger. The decision of Cas will not hold me back," Semenya notes.

"I will once again rise above and continue to inspire young women and athletes in South Africa and around the world."

The ruling means IAAF will compel Semenya, 28, and other "hyperandrogenic" athletes or those with Differences of Sexual Development (DSD) to take drugs to lower their testosterone levels below a prescribed amount for them to be allowed to continue competing.

The rules were introduced in 2018 but have not taken effect due to the case filed by Semenya.

Earlier this year, Semenya issued a statement declaring that she's "unquestionably a woman."

Although CAS has found the rules to be discriminatory, it notes that the discrimination is "necessary, reasonable and proportionate" to protect "the integrity of female athletics".

Semenya can appeal against the CAS ruling to the Swiss Tribunal Courts within the next 30 days.