Indian sprinter Dutee Chand vowed Tuesday to fight any efforts to bar her from the sport, after new research showed runners born with high testosterone levels enjoy a "significant competitive advantage".
The 21-year-old was banned after being diagnosed in 2014 with hyperandrogenism -- a condition that causes high natural levels of the hormone in women.
She contested the ban and won a temporary reprieve from the Court of Arbitration for Sports (CAS) which allowed her to compete.
Without proof, the International Association of Athletics Federations (IAAF) regulations excluding women with hyperandrogenism from competition are set to lapse this year.
But the global body plans to submit the new research as evidence to back its case that they should remain in place.
"I know that my case is going to start all over again but I am not afraid of anything," Chand told AFP by phone.
"I am confident I will come out unscathed. I will keep fighting until I get justice. A positive ruling will not only benefit me but all other women athletes like me."
The IAAF introduced the regulations in 2011 after a highly emotive public battle with South Africa's two-time Olympic champion Caster Semenya.
It part-funded the latest research, which relied on data from more than 2,100 blood samples taken from male and female athletes.
Testosterone, which can also be injected as a performance-enhancer, increases muscle mass and boosts physical strength.
The issue of hyperandrogenism is controversial because it has pitted principles of fair competition against the rights of women born with a condition they have no control over.
The IAAF rules allowed hyperandrogenic athletes to take medication to lower their testosterone levels to below 10 nanomoles per litre -- considered a low level in men.
The natural range for women is about 10 times lower.
Chand, who won two bronze medals at the recent Asian Athletics Championship in her home state of Orissa, said she was not alone in her fight against "cruel and discriminatory" rules.
"There are other athletes who are suffering like me without any fault. The whole world is supporting me."