Most people either lift weights or do cardio. The smart ones, of course, do both: They lift and follow that with cardio when their blood sugar has been exhausted and bodyfat is more easily tapped. Now new evidence suggests that combining weights and cardio suppresses appetite. According to the April ’09 Prevention, a study in the Journal of Sports Science and Medicine found that trainees who combine weight training and aerobics tend to eat less—500 fewer calories a day—than those who do cardio alone. The researchers suggest that the dual-action workouts increase satiety hormones.