Objective: To develop overall core stability and strength. Technique: Lie supine (on your back) on the ball, arching your entire torso over the ball. Ensure that your shoulder blades, back, and glutes are on the ball, allowing full extension of your ab’s. Activate your core by pulling your belly button in and up towards your spine then slowly roll your hips and chest up at the same time. Crunch from the top of your torso and then lower yourself slowly back to the starting position.