This exercise enhances balance, core stability, and core strength.

Start with both hands on the ball. One leg at a time, bring your knees up onto the ball. Once you have gained your balance in this position, slowly extend one leg outwards behind you, until it is straight out behind you parallel to the ground and in a straight line with your back. Keep your abs engaged and maintain normal breathing throughout the exercise. Hold for 5-10 seconds. Return to starting position with both hands and knees on the ball, and repeat with opposite leg.