“People who say, ‘This is nothing; we don’t need this rule,’ don’t know sports or are at some distance from sport,” Ljungqvist said. “This is not an easy matter. It’s an evolving matter. We just can’t bury our heads in the sand and pretend these conditions do not exist.”

The I.O.C. chose testosterone as a way to differentiate men from women because it is known to increase strength and muscle mass, and to help bodies recover from workouts. Female athletes with high testosterone can still have levels well above the average range for women. They just need to be below what the I.O.C. deems as the men’s range.

The study from the 2011 world championships said testosterone levels for women in the 99th percentile were 3.08 nanomoles per liter, which is markedly lower — “extraordinarily lower,” according to Vilain — than the 10 nanomoles per liter which the I.A.A.F. has set as the lower end for the male range.

Chand’s testosterone tests above that lower limit for men. But her supporters say testosterone should not be used as a gauge, because there has been no scientific published proof that it alone conveys an athletic advantage, especially when that testosterone is naturally produced. Critics say it is impossible to provide such proof because giving athletes testosterone to study its effects would be unethical.

Chand has a simpler take.

“If you make an elephant run, can that elephant run fast, even though he has a lot of strength?” she said. “Not necessarily. It’s all about training.”

The case is likely to take months to decide. Chand will remain in limbo, worried that her childhood dream will permanently derail.

The daughter of weavers who make about $8 a week, Chand was about 4 when she started tagging along with her elder sister, one of her six siblings, for workouts on a local track. By the time she was 10, she was living three hours from home and training in a national program, thrilled that she could send her prize money to her family. With her financial help, her parents eventually moved out of their two-room, no-toilet mud hut into a four-room house.