This exercise provided courtesy of Mike Clausen, founder and co-owner of DIAKADI Body training gym, voted best personal training gym in San Francisco by CitySearch in 2006.
Medicine ball sit-ups ensure your abs work doubly hard, as they lift not just the weight of your upper body but the weight of the ball. By keeping your legs flat through this exercise, you further isolate your core.
Lie on your back on the floor with your legs extended and a medicine ball held in both hands above you. Extend your arms toward the ceiling so that your arms are perpendicular to the floor and the medicine ball is directly over your upper chest (see Photo 1).
- From the starting position, engage your abs by bringing your belly button toward your spine. Do not tip your pelvis upward. From that engaged position, begin lifting your shoulders off the floor in a sit-up, taking your arms forward as your upper body rises. Your legs should remain flat. Do not fling your upper body upward, nor grab through your lower back. Instead, think of peeling your shoulders off the floor from your center, and try to feel that the medicine ball is pulling you from above (see Photo 2).
- Come as close as you can to sitting upright, with your arms extended forward and your legs still flat on the floor (see Photo 3).
- From the top of the motion, reverse direction and lower back to the starting position. Control this downward movement using your abs—but make sure you use your lower abs, not just the area up by your rib cage. Be careful that the bottom part of the motion doesn’t happen more quickly than the top part; you want to lower yourself at a continuous pace (see Photos 4 and 5).
- At the bottom of the motion, move immediately into your next sit-up.