In February, Trump signed an executive order titled “Keeping Men Out of Women’s Sports,” which gave federal agencies the ability to penalize schools for allowing transgender athletes to compete — something the Trump administration says violates Title IX, the federal civil rights law that prohibits sexual discrimination.

What are the stakes when a fraction of a second, the length of an extended arm or the weight of a body in motion can mean the difference between victory and defeat?

The president said he would withhold federal funding, saying it was “totally unfair” for transgender athletes to compete in girls’ and women’s sports.