When training the core it is very important to remember not to focus solely on only the abdominals. I see many people who are striving for that washboard stomach doing hundreds of crunches, yet forgetting about their back muscles. This will lead to muscle imbalance of the core and eventual back pain.
In any core conditioning program you should aim to have the total amount of flexion (abdominal) exercises equal to, or very close to, the total amount of extension (back) exercises.
Another thing I want to stress is the importance of training with correct technique. There is only one correct way to do each exercise, so make sure you know it. Performing exercises incorrectly will result in the wrong muscles being worked during the exercise. Over time, this could lead to postural abnormalities and injury.
When performing abdominal exercises I generally recommend a repetition range of 15-20 reps. The goal is to work the muscles to fatigue, not failure. By fatigue I mean working the muscle until you can no longer perform the exercise with correct technique. You do not want to go to failure, which I refer to as not being able to complete the exercise with bad technique.
I often hear people complain of their necks hurting when they do abdominal exercises. To help stabilize your neck muscles, so your neck doesn’t get tired, try placing your tongue on the roof of your mouth just behind your teeth.
Here are a few of my favorite stability ball core exercises. Remember 15-20 reps of each. If this is too easy, slow down the tempo of the exercise or add weight. Perform 2-3 sets of each exercise with about 30 seconds rest in between sets.
You may also perform these exercises in a circuit style. Move from one exercise to the next with little to no rest until all exercises have been completed. Rest 2-3 minutes and then repeat the circuit. This is personally my favorite way to do these exercises.
Back Extension
- Place the feet against a wall or secure them under an object & position the hips over the stability ball with the hands behind the head & the elbows wide.
- Keep the hips & legs stationary & extend the spine then reverse the movements back to the start position.
- Extend up to a neutral position. Keep the neck in line with the spine & control both phases of the movements.

Back Extension with Rotation
- Place the feet against a wall or secure them under an object. Position the hips over the stability ball with the hands above the head.
- Keeping the hips & legs stationary, extend & rotate the spine then reverse the movements back to the start position.
- Keep the neck in line with the spine & control both phases of the movements.
- Repeat 15-20 each side either alternating sides, or continuously to the same side then switching.

Oblique Crunch
- Position the hips over the stability ball with the feet supported against a wall, the hands behind the head & the elbows wide.
- Starting in a laterally flexed position, raise the body up as high as comfortable then return to the start position.
- Do 15-20 reps then repeat on other side.

Oblique Crunch with Rotation
- Position the hips over the stability ball with the feet supported against a wall, the hands behind the head & the elbows wide.
- Starting in a laterally flexed position, rotate the torso & raise the body up as high as comfortable then reverse the movements back to the start position.
- Do 15-20 reps then repeat on other side.

Crunch with Rotation
- Start with the lower back over the stability ball with the arms above the head & the toes resting against the wall.
- Keep the hips & legs stationary & flex & rotate the torso to raise the shoulders off the ball. Keep the arms in line with the torso then reverse the movement back to the start position.
- Repeat 15-20 each side either alternating sides, or continuously to the same side then switching.

Crunch
- Start extended over the stability ball with the feet flat on the ground, the hands above the head & the elbows wide.
- Secure the feet under dumbbells or something similar to prevent the feet from lifting off the ground
- Keeping the hips still, flex the upper body to take the shoulders off the ball.

Opposite Arm and Leg Raise
- Start with the hands under the shoulders & the feet on the ball.
- Maintain a rigid torso and raise one arm & the opposite leg off the ball.
- Hold this position for up to 20 seconds and then switch sides.
