1. Lie on your back with your ankles resting on the ball.
2. Look up at the ceiling, and keep your chin relaxed. You can place a small pillow under your head or neck for comfort.
3. With your arms by your side, press your hands onto the floor for stability.
4. Tighten your belly muscles by pulling in your belly button toward your spine.
5. Push your heels down toward the floor, squeeze your buttocks, and lift your hips off the floor until your shoulders, hips, and knees are all in a straight line.
6. While holding the bridge position, roll the ball toward you with your heels. Keep your hips as level as you can.
7. Pause briefly, and then roll the ball back out. Try to keep the ball rolling straight. You will feel the muscles in your lower belly working as you straighten your legs.
8. Lower your hips.
9. Return to your starting position.
10. Repeat 8 to 12 times.

When you can keep your body and the ball steady throughout this exercise, you're ready for more challenge. Try keeping your hips raised while rolling the ball out, holding the bridge, and rolling back, a few times in a row.