Push-Up on a Ball
Once you nail the whole balancing-on-a-teetering-object thing, the actual push-up part of this exercise feels like a triumph. (Note: If you've had knee joint or nearby ligament injuries in the past, don't let the ball rest directly on your kneecaps -- the pressure plus lack of stability flares mine up if I'm not careful.)
- Lie with your abdomen on an exercise ball and walk your hands forward on the floor until the ball rests under your thighs.
- Pull your navel in toward your spine, bending your elbows.
- Lower your upper body to the floor. Hold this position for three seconds, and then push up so your elbows are straight, but not locked. Keep your head in line with your spine and your abs engaged.
- Start with 5 reps, working up to 15. Once you've mastered 15 reps, rest for one minute and then do a second set.