It is increasingly difficult to figure out. Shooters take drugs to slow their heartbeats. Gymnasts take drugs to stunt their growth. Lifters take drugs to increase body mass. Distance runners take drugs to increase blood oxygen.
Swimmers take drugs to increase endurance.
And Cuba's Javier Sotomayor, who is competing after a shortened ban for a positive cocaine test, evidently took drugs for the fun of it, though he denies it. And so we watch for the purity of competition, and we wonder about the purity of blood. Take the swimming. She won three golds, flashing through the water like nothing you've ever seen before. Maybe you have.