IAAF testosterone rules

CAS dismisses Semenya appeal

South African Semenya, the double defending Olympic champion over 800 metres, and Athletics South Africa had challenged the IAAF's new regulations concerning athletes with differences of sex development (DSD).

The rules in question require athletes with naturally-occurring high levels of testosterone to take medication to reduce those levels, in order to compete in women's track events ranging from 400m to a mile.