Ever since Congress passed the federal gender-equity law known as Title IX, universities have opened their gyms and athletic fields to millions of women who previously did not have chances to play. But as women have surged into a majority on campus in recent years, many institutions have resorted to subterfuge to make it look as if they are offering more spots to women.

At the University of South Florida, more than half of the 71 women on the cross-country roster failed to run a race in 2009. Asked about it, a few laughed and said they did not know they were on the team.

At Marshall University, the women’s tennis coach recently invited three freshmen onto the team even though he knew they were not good enough to practice against his scholarship athletes, let alone compete. They could come to practice whenever they liked, he told them, and would not have to travel with the team.

At Cornell, only when the 34 fencers on the women’s team take off their protective masks at practice does it become clear that 15 of them are men. Texas A&M and Duke are among the elite women’s basketball teams that also take advantage of a federal loophole that allows them to report male practice players as female participants.