Semenya loses landmark case against IAAF testosterone rules

Double Olympic champion Caster Semenya has lost her appeal against the introduction of new rules regulating the testosterone levels for athletes with a difference in sex development (DSD).

The Court of Arbitration for Sport (CAS) announced that its panel had rejected the South African's challenge against the IAAF' "by majority" but did add that it had "serious concerns as to the future practical application" of the new rules.

Olympic 800m champion Semenya, 28, said in response to the ruling that the IAAF "have always targeted me specifically".

"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," the statement continued.

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

Previously, she had said that she wanted to "run naturally, the way I was born".

Now she - and other athletes with differences of sexual development (DSD) - must either take medication in order to compete in track events from 400m to the mile, or change to another distance.

Cas found that the rules for athletes with DSD were discriminatory - but that the discrimination was "necessary, reasonable and proportionate" to protect "the integrity of female athletics".

However, Cas set out serious concerns about the application of the rules and has asked the IAAF to consider delaying the application of the rules to the 1500m and one mile events until more evidence is available.

The IAAF has said it will make an exception for athletes wishing to compete under the new regulations at the World Championships in Doha this September.

Though the event is less than six months away, Semenya and other similar athletes will be allowed to begin taking medication before the end of this week, and for the next five months, to be eligible.

A statement from the IAAF said that no athlete "will be forced to undergo any assessment" and that any treatment was up to the individual athlete.

"Sometimes it's better to react with no reaction," tweeted Semenya after the verdict was announced.