Equipment
Medicine Ball
Body Parts
Abs

Step-by-step instructions

1. Hold the ball with both hands in front of your chest and sit on the floor.
2. Anchor your feet under something sturdy for support, and lie back on the floor a few feet away from a brick or concrete wall.
3. Explosively sit up and throw the ball into the wall and then catch it on the rebound. If you have a partner, you can throw the ball to him instead and let him throw it back.