South Africa’s Caster Semenya returns to the track tonight. AP Photo
A defiant and proud Caster Semenya will be lining up in her preferred 800m event in Doha tonight just five days before the IAAF’s controversial female eligibility rules go into effect.

It could be the last time the South African lines up in her favourite two-lap event without any IAAF imposed constraints.

Semenya was not on the starting lists when the Court of Arbitration for Sport (CAS) made its landmark ruling in favour of the IAAF on Wednesday.

The IAAF has been given the go-ahead to implement its controversial policy that requires female athletes with Differences of Sexual Development (DSD) to reduce their testosterone concentration to less than five nanomoles per litre of blood.

The regulations will go into effect next Wednesday, requiring athletes to maintain the levels for six months while it will also only be limited to events between the 400m and the mile.

Semenya’s career hangs in the balance as she weighs up whether she should comply with the regulations by taking the hormone reducing medication to compete in the restricted events.

“Relevant Athletes have one week (seven days) from today (1 May) to reduce testosterone levels to within the regulation levels so are encouraged to initiate their suppressive treatment as soon as possible,” the IAAF said in a statement on Wednesday following the CAS verdict.

“The IAAF will accept that relevant athletes who comply with the five nmol/L limit starting on or before 8 May 2019 will be eligible for the IAAF World Championships Doha 2019, assuming they meet the other required eligibility conditions.”

Semenya could still compete unrestricted in the sprint events or the distances above the mile.

She made her maiden sojourn into the 5 000m earlier this year and won her first South African title in the distance.

The 28-year-old will be looking to continue her unbeaten record in the 800m in tonight’s race in Doha.

The two-time Olympic champion has been undefeated in the 800m for three years.

She has won just short of 30 consecutive two-lap final races since September 2015 and will be looking to go out with a bang in her beloved event.

The CAS panel voiced its reservations about the IAAF’s evidence to include the mile and the 1 500m in the restricted events.

“The difficulty to rely on concrete evidence of actual (in contrast to theoretical) significant athletic advantage by a sufficient number of 46 XY DSD athletes in the 1500m and 1-mile events,” the CAS said.

“The CAS panel suggested that the IAAF consider deferring the application of the DSD Regulations to these events until more evidence is available.”

While this looked like a possible lifeline for Semenya, it is unlikely the IAAF would make any changes to the current regulations.

World youth and junior 400m hurdles champion Zeney van der Walt and Commonwealth Games bronze medallist Wenda Nel will be the only South Africans joining Semenya in Doha.

Van der Walt won her first senior SA title last weekend when she beat Nel in the one-lap hurdles event