 Caster Cmenya Loses Testosterone Fight South African runner Caster Cmenya today lost her court challenge against IAAF rules forcing female athletes to regulate their testosterone levels, but judges voiced concern with the application of the discriminatory regulations. Cmenya, a double Olympic champion, was fighting measures imposed by the International Association of Athletics Federations, IAAF, that compel hyperandrogenic athletes, or those with differences of sexual development, DST, to lower their testosterone levels if they wish to compete as women. A three-judge panel at the Court of Arbitration for Sport said it had some serious concerns as to the future practical application of these DST regulations. Even though the regulations are discriminatory, such discrimination is a necessary, reasonable, and proportionate means of achieving the IAAF's aim of preserving the integrity of female athletics in the restricted events, the Los An based court said in a statement. The IAAF insisted the rules were essential to preserve a level playing field and ensure that all female athletes can see a path to success. The verdict is certain to cause controversy, as Cmenya was backed by a global coalition of nations and scientific experts who argued that testosterone is an arbitrary and unfair measure for determining gender. Experts also stressed that achieving excellence in sport is a combination of training and commitment as well as genetics and that barring people from competition over a single genetic factor has no scientific basis. In a rare intrusion into the world of sport, the United Nations Human Rights Council adopted a resolution last month branding the IAAF rules unnecessary, humiliating and harmful. The IAAF has countered that DST athletes with male levels of testosterone get the same increases in bone and muscle size and strength and increases in hemoglobin that a male gets when they go through puberty. Cmenya's testosterone levels are not publicly known, but she is unlikely to be the only athlete affected by Wednesday's verdict. The two athletes who finished behind her in the Rio Olympics 800M, Francine Nyansaba of Burundi and Kenya's Marguerite Guambui, have also faced questions about their testosterone levels. However, the judges want the IAAF to apply the rules only up to the 800M because the evidence was not clear that women with hyperandrogenism have a competitive advantage in the 1500M. The CAW panel suggested that the IAAF consider deferring the application of the DST regulations to these events, 1500M and a mile, until more evidence is available, the court said. That could give Cmenya a route to compete at the world championships without taking medication. She was the bronze medalist in the 1500M at the 2017 Worlds in London. A further appeal is possible to Switzerland's Supreme Court in Lausanne. Federal judges rarely overturn CAW decisions, but can intervene if legal process was abused.