Primary Muscle Group: Core Muscles

Muscle groups worked in this exercise: Abdominus Rectus

Preparation: Lying on your back, bent your knees and place your feet on the floor. Hold the ball straight up above your chest. Bring both knees in toward your chest.

Execution: The only difference here is that you will also lift your head and shoulders while performing leg extensions and bringing them back to center. This simultaneously targets both upper and lower abdominal areas.