A new scientific paper finds that women who produce higher-than-normal amounts of testosterone have up to a 4.5 per cent advantage over their competition on the track.
World track officials plan to use this evidence to potentially sideline Olympic gold medallist Caster Semenya and others with so-called intersex conditions.
The International Association of Athletics Federations will submit the study in its appeal to the Court of Arbitration for Sport. The top sports court suspended an IAAF rule that enforced a limit on female athletes' naturally occurring testosterone levels.
The appeal will not affect next month's world championships, where Semenya is expected to go for her third title at 800 metres.
The study analyzed more than 2,100 androgen samples from athletes participating in the 2011 and 2013 world championships.
