IAAF issues new testosterone rules for female athletes
World athletics body, the IAAF has introduced rules for female track athletes.
The federation says women who have higher levels of testosterone, also known as hyperandrogenism, will have to take medication daily for half a year before they're able to compete in international tournaments.
They'll have to reduce their testorone levels to one that's acceptable.
These new regulations affect events including the 400-metre race, the 800-metre and 1500-metre.
The changes will affect South African sprint champion, Caster Semenya who could be forced to lower her testosterone levels again if she wants to continue competing.
The regulations come into effect in November.