Lie on your back, knees bent, feet flat on the floor and close to buttocks. Place one hand on your belly and the other under the small of your back, palm up. Hold your transverse in at the fifth floor, lift your feet off the ground one at a time and bring your knees up over your hips [A]. Keeping your transverse in, slowly put one foot on the ground and slide your heel until the leg is straight [B]. Slowly slide your heel back toward your buttocks and then lift it up to the starting position [A]. Switch legs. Do 15 alternating slides (30 total). If you can't hold your transverse in while doing the slide, wait until you feel strong enough to try this exercise. Strengthens abs.