This exercise provided courtesy of Billy Polson, founder and co-owner of DIAKADI Body training gym, voted best personal training gym in San Francisco by CitySearch in 2006.
The stability ball builds strength by demanding balance. Use this set of variations on standard hip raises to push your legs and hips to the limits of endurance.
Lie on your back on the floor with a stability ball under your heels and your legs extended. Your legs should be straight and your arms should be at your sides, palms down (see Photo 1).
- From the starting position, raise your hips until they are fully open (see Photo 2).
- Lower your hips slowly but stop just above the floor; then repeat the hip raise. Do not let your hips touch the floor between repetitions for a set of 10 hip raises.
- On the final hip raise, hold your position at the top and begin heel curls. Slowly roll the ball in toward you by bending your knees, keeping your hips raised and your heels on the ball. Once you have rolled the ball as close to you as you can, press it slowly back out, keeping your hips raised throughout (see Photo 3).
- After you have completed 10 heel curls, bring the ball to the midway point of a heel curl, such that your knees are bent and your hips are still off the floor. Place the soles of your feet on the ball, rather than your heels, and slowly perform a set of 10 hip raises, lowering almost to the floor and then raising back up to an open hip position at the top (see Photos 4 and 5).
- Finally, keeping your hips off the floor, roll the ball away from you and walk your feet down its side until you can only just reach it with the balls of your feet when your knees are slightly bent. Driving through your toes, perform hip raises for a set of 10 repetitions, being careful again not to drop your hips all the way to the floor between raises, and pressing firmly into the ball to prevent slipping (see Photos 6 and 7). If this final variation proves tricky, you can put the ball against a wall or a machine for stability.