If so, you probably find yourself at the gym more often than your laid-back friends. A new study by the University of Pennsylvania found that people who were really nice and encouraging of others were less likely to work out than people who were more cutthroat and competitive. And that was true even when people were doing NON-competitive activities – like yoga and pilates. Exercisers who focused on being better than their fellow gym-goers, or who were trying to beat their personal best, went to 90% more classes. So the researchers concluded people with a competitive streak in their personality are more likely to exercise.