Develop incredible abs with a medicine ball (one of 8-10 pounds is optimal) and this three-exercise circuit. Work up to three circuits.
Lie on your back, with your hips and knees bent and your feet off the floor. Rest your hands lightly on your chest. Position the ball between your knees.
Exhale as you lift your shoulders off the floor and bring your knees toward your chest. Grab the ball with your hands and bring it to your chest as you inhale. Return your shoulders and legs to the starting position. Transfer the ball back to your legs on the next repetition. Alternate ball positions for the entire set. Do eight to 12 repetitions for two sets.
Sit on the floor, your back straight but leaning slightly toward the floor, as if in the “up” position of a situp. Your knees should be bent 90 degrees, your heels about 15 inches apart and resting on the floor. Hold the ball close to your chest, rotate your torso to the left, and place the ball on the floor behind you. Rotate around to the right, pick up the ball, rotate left, and place it behind you. Repeat eight to 12 times, then do eight to 12 more starting with a rotation to your right; that’s one set.
Reverse Crunch with Knee Drops
Lie on your back, hands resting on the floor at your sides, hips and knees bent 90 degrees, and feet off the floor. Position the ball between your knees. Keep your lower back on the floor throughout the exercise. Contract your abdominals and pull your knees to your chest, then return them to the starting position. Lower your knees to the left and return to the starting position. Drop your knees to your right on the next repetition, and alternate sides for each rep. Do two sets of 12 reps.