The National Collegiate Athletic Association (N.C.A.A.) has its own guidelines on transgender athletes, which have to do with testosterone levels. Testosterone, a hormone that helps build muscle mass, is present at higher levels in most adult men than in most adult women. To qualify for competition, the N.C.A.A. mandates that transgender women complete 12 months of hormone therapy to suppress testosterone as part of their gender transition before competing. (The Olympics also allows transgender women to compete against other women if they suppress their testosterone.)
Under those guidelines, Hecox, who began hormone replacement therapy in 2019, would qualify to compete on the women’s team at Boise State. But the new law in Idaho, if the courts uphold it, would supersede the N.C.A.A.’s regulations in that state.
Although Idaho and Mississippi are the first states to pass laws barring transgender female athletes from women’s sports, many states’ high school athletics associations have their own rules. In some states, such as Arkansas and Indiana, students must compete against others with the same sex listed on their birth certificates. Other states, such as Missouri and Ohio, have rules similar to the N.C.A.A.’s, requiring hormone intervention for transgender athletes. And in 16 states and Washington, D.C., students can participate in sports based on their gender identity without restrictions, according to Transathlete.com, which tracks these policies.
One reason school officials haven’t been able to reach a consensus is that the scientific research on whether it’s possible to achieve athletic fairness through hormone therapy is limited. Even if more research is made available, many transgender rights advocates argue that students shouldn’t have to alter their bodies just to play sports.