Purpose: This helps to strengthen your abdominal (stomach) muscles. Your ab muscles are important to protect your back from being injured while playing sports and they help to control your arms and legs while running, throwing, swimming, jumping, and cutting.
How to do it:
* Lie on your back with both of your knees bent.
* Tighten your stomach and press your back flat into the ground.
* Slowly pull one knee up towards your chest, then return it back to the starting position while lifting your other knee towards your chest.
* Continue to move your legs back and forth as if you are riding a bicycle.
* Repeat 30 times (each heel tap counts as 1).