Caster Semenya lost her appeal against rules designed to decrease naturally high testosterone levels in some female runners.
The Court of Arbitration for Sport announced its ruling Wednesday, backing the IAAF, the sport’s international governing body.
The IAAF, after funding a study along with the World Anti-Doping Agency, said last year that research showed the following natural testosterone levels:
Most women: .12-1.79 nanomoles per liter in blood
Normal men after puberty: 7.7-29.4 nmol/L
The new rule forces all who race the women’s 400m through the mile and who are androgen-sensitive to restrict their ratio to below five.