The primary muscle groups you work are the rectus abdominis better known as your six pack muscles, the transverse abdominals and your oblique’s. It is important to have the proper posture in order to get the full benefits and activate all muscle groups.
Start out by lying on your back with your hands behind your head and pull up to a partial crunch until your back has slightly lifted off then rest back down. Do not pull on your neck to initiate the crunch.
Once you've mastered the move, you can try more difficult exercises. We recommend three sets of eight to 12 reps, resting for 1 minute between sets.
1. Glute Lift -
Sit on a Stability ball with your feet flat on the floor, shoulder-width with your back on the stability ball. Make sure your shoulders, neck and head are lined up and properly supported, and keep your knees at a 90 degree angle and your torso flat. Slowly squat to the ground moving your hips downward with out making the ball roll and hold. Then move your hips back up squeezing your glute muscles until you have returned to the starting position. Roll back in forth slowly working each muscle group and squeezing abs and glutes while in the bridge position.
2. Back Extension
Lay on the ball stomach down and position your hips and torso with the knees slightly bent. Put your hands on the back of your head or crossed behind you, and gently lift your torso up, and lift your shoulders up to end in a straight posistion with your body. Ensure your neck, head, back and shoulders are all lined up properly and you squeeze your abs without over extending int he back.
3. Hip Lift
Lie on the floor with your feet extended up on the ball. Squeeze your abs in tightly, gently raise your hips off of the ground with you glutes tightly squeezed until you reach a straight position. Keep the position for a few counts then release. For a more advanced workout try raising your hips then raise one leg off of the ball and hold for a few counts then lower.
4. Ball Switch
Lie on your back holding the stability ball between your feet. Slowly raise your legs while lifting your head, neck and shoulders with your hands out. Meet your feet in a V position and pass the stability ball to your arms and slowly lower your legs and upper body and the same time.