STANFORD, California - Olympic champion Caster Semenya said on Sunday she would not defend her world title in Doha in September if she cannot run in the 800 meters because of new testosterone regulations imposed by the sport's governing body.

"If I am not running the 800m, I'm not running in the world championships," the South African said after winning her favorite event in one minute, 55.70 seconds at the Prefontaine Classic Diamond League meeting in California.

"No 1,500 (meters), nothing. I am just going to take a vacation, and then come (back to competing) next year."

But the 28-year-old, who is challenging International Association of Athletics Federations (IAAF) testosterone rules that could affect her career, is looking towards the next three Olympics.

"I expect to be in Tokyo, Paris and Los Angeles," she said

Semenya repeated that she would not take medication to satisfy the IAAF regulations, which are currently on hold for her after a court ruling.

Under the rules, XY chromosome athletes with differences in sexual development (DSDs), like Semenya, must take medication to lower their natural testosterone levels if they are to compete at distances from 400m to a mile.

Testosterone is a hormone that increases muscle mass, strength and hemoglobin levels and the IAAF said its own research showed it gave a significant endurance advantage to athletes in the 400m-to-mile range.

Semenya has refused to take the medication, saying: "I am a woman and I am a world-class athlete. The IAAF will not drug me or stop me from being who I am."

But she said that even if she eventually lost her case, she planned to continue competing.

"There are a lot of races that I can do, there is a lot of stuff that I can do," she said.

"I am a talented athlete. I can play football (soccer), I can play basketball, I can do anything.

"I can run 100, I can run 200, I can run the steeplechase. I can do anything I want."

Semenya charged ahead about 600m into Sunday's race and won by almost 15m over American Ajee Wilson to claim her 31st consecutive final in the event. She last lost an 800m final in Berlin on Sept 6, 2015.

The race was the fastest ever run in the United States, but three-time world champion Semenya said she felt sluggish.

"I would be still sleeping at home, "she said, noting it was about midnight in South Africa.

The competition was Semenya's first since the Swiss Federal Tribunal said she did not have to adhere to the IAAF regulations until her appeal against a Court of Arbitration for Sport (CAS) ruling in favor of the new rules is decided.

The IAAF has said the regulations are necessary to preserve the integrity of female athletics in the restricted events.

Reuters