Caster Semenya, a South African athlete with unusually high testosterone for a woman, has lost her appeal against new regulations from the International Association of Athletics Federations. The regulations set an upper limit on how much testosterone a female athlete is allowed to have compete in middle distance running, and require any woman over this limit to artificially lower her testosterone if she wants to continue competing. Ruby Osborn discussed the story. Like this podcast? Please help us by supporting the Naked Scientists