Caster Semenya has lost a landmark case against athletics’ governing body meaning it will be allowed to restrict testosterone levels in female runners.
The Court of Arbitration for Sport (Cas) rejected the South African’s challenge against the IAAF’s new rules.
But Cas said it had “serious concerns as to the future practical application” of the new rules.
Semenya, 28, had said the regulations were “unfair” and that she wanted to “run naturally, the way I was born”.
Now she – and other athletes with differences of sexual development (DSD) – must either take medication in order to compete in events from 400m to the mile, or change events.