Lie on your back on Sit Up Mat, bending your knees to about 90° with your feet flat on the floor. Grasp handles on mat. Raise your torso, shoulders, and head 6 to 12 inches. Tense your abdominal muscles and hold this position for a few seconds. Return slowly to the floor and repeat. Don't overdo it. One set of 5 properly executed sit-ups is enough at first. Add 1 sit-up each workout until you reach 15, then add more sets.