This AeroPilates Level Three Simply Cardio Workout, with its mix of fun Free-Form Cardio Rebounding positions, will kick up your metabolism and burn calories. Studies have shown that AeroPilates Free-Form Cardio Rebounding is one of the most effective cardiovascular exercises you can do. Because you rebound while lying down, your spine, hips, knees, ankles and feet are totally protected from the stress of impact, while gravity assists in raising your heart rate with less effort than other forms of aerobic exercise.