This is a simple crunch exercise on the ball.

1. Start by sitting on top of the exercise ball. Roll forward until your lower back is supported by the ball. Place your hands behind ears or have them folded across the chest.

   

2. Crunch forward until you are at a 45 degree angle to the ball. Keep your neck in a neutral position.

   

3. Lower yourself slowly, making sure that you don't go too far back, and feel back pain. Hold for 2 seconds and return to start position for one full rep.

   

4. Recommended reps: 12-15 to start, and increase as you progress.