A new study shows that a bit of competition works best if you want to motivate yourself to exercise regularly. 800 graduate and professional students were put through an 11- week exercise program with running, spinning, yoga, Pilates and weightlifting classes. Each person was assigned to work out alone or in a team, and the dynamics were designed to be either socially supportive or competitive. Whether a person was alone or in a team didn’t affect how many workouts they did. But a competitive atmosphere encouraged people to work out more across the board. People who were in the competitive groups went to 90 percent more classes than those who weren’t.