The IAAF announced on Tuesday that they will delay implementing new guidelines on female testosterone levels. 

The governing body originally set a November 1st deadline for the regulations which create a maximum amount of natural testosterone for women competing in events from the 400 meters to the mile. But the new ruling was quickly challenged by Caster Semenya, who brought the case to the Court of Arbitration for Sport (CAS). 

Under the new timeline, the IAAF will push enforcing the new rule until March 26th. The CAS hearing is scheduled to take place in February.

But the delay could mean a larger impact on the track and field season. This is in part due to a six-month “suppression period” that affected athletes would have to sit out if their levels are out of the acceptable range.

To combat this, and still allow athletes to compete during next summer’s track season, the IAAF will allow athletes to begin their six-month period before the rule is officially enacted.   

“Athletes wishing to begin their six-month period sooner than the end of March should contact me directly,” said Stéphane Bermon, the IAAF’s Health & Science Department Director.

In July, researchers called on the IAAF to retract the study that led to the testosterone regulations, citing flaws in the data.