HOW: Start with one foot on a soccer ball or similar ball like a medicine ball. Jump with the leg not on the ball and land softly with the opposite leg. The leg that jumped should now be positioned with one foot on the ball. Alternate tapping the balls of your feet onto the ball making sure to land softly with each jump. Go as fast as you can control making sure to just tap the ball with your foot.
FEEL: You should feel the muscles in your calves primarily working.
COMPENSATION: Keep your back straight up, don’t slouch. Land softly with the leg that is going from the ball to the floor. Touch the ball with just the balls of your feet, not kicking the ball with your whole foot.