Flatten Your Stomach With a Swiss BallEveryone wants a flat stomach but if you think the best way to get one is by doing sit-ups or crunches, I have a BIG surprise for you!

Crunches primarily work the large outer muscles of the core (the rectus abdominis and the external obliques). When overdone or performed incorrectly, these kinds of exercises can worsen your posture and increase the โ€œpoochinessโ€ of your abs.

Flattening the abs requires correct exercise, good eating habits and a supportive lifestyle. No matter how much you exercise, you won’t get a flat stomach if you insist on filling it with fast food or excessive amounts of alcohol!

To narrow the scope of this article, we’ll look at exercises you can use to flatten your stomach and leave the diet and lifestyle issues for another time.

The Inner and Outer Units

The anatomy and actions of the abdominal wall are quite complex, but can be divided into two parts: The inner unit and outer unit.

In simple terms, the inner unit provides stability for the spine, support for your viscera and a working foundation from which the arms and legs can operate without beating the spine up.

Flatten Your Stomach With a Swiss Ball

Outer Unit

Flatten Your Stomach With a Swiss Ball

Inner Unit






















The outer unit creates โ€œsling systemsโ€ which connect the arms, core and legs for all the types of movements we need to do each day, including walking, running, throwing and lifting.

An exercise program designed to condition the abs for both aesthetic and functional purposes needs to work on both the inner and outer units. One of the best tools you can use to condition your abs is the Swiss ball.

The Swiss Ball Rules

Before you begin this specialized exercise program to flatten your stomach, you’ll need to follow some important “rules of the road.”

1. Pay close attention to each detail of the exercise. Many Swiss ball exercises look deceptively easy, but the smallest deviation from the correct technique can alter the effect of the entire exercise.

A Swiss ball exercise performed incorrectly can worsen the muscle imbalances and strength deficits that it should be correcting.

2. Follow the Form Principle. Each repetition of each set of any exercise should be performed perfectly. Once the muscles and nervous system become fatigued, the quality of the repetitions will fall, and the exercise is no longer beneficial.

Athletes who may be very strong in regular training programs can find Swiss ball exercises quite challenging, as they are often working muscles in new and different ways. Stick to the Form Principle and do not attempt to do the more advanced levels of these exercises until you are ready for them.

Start each exercise at the โ€œstabilityโ€ level. Once you can perform each exercise for the required numbers of reps and sets at this level, then progress to the โ€œstrengthโ€ level.

If you don’t build stability first, you will overwork the outer unit without the necessary conditioning of the inner unit to support it. This would be like putting a new V-8 engine in an old rusty banger of a car without also replacing the shocks, suspension and brakes!

3. Make sure you are using a burst-resistant Swiss ball with a rating high enough to support your body weight, as it should be fully inflated so it is firm.

Sit upright on the ball with your feet on the floor. Your thighs should be parallel or a little above parallel to the floor. If you have low back pain, it is better to have your thighs slightly above parallel. In general, for people who are 1.50-1.68 meters tall (about 5-5.5 feet), use a 55 cm ball. For those who are 1.70-1.83 meters tall (5.5-6 feet), use a 65 cm ball. For folks who are taller than 1.85 meters (6 feet), use a 75 cm ball.

Prone Jackknife

The prone jackknife is a great exercise for integrating shoulder, core and hip flexor strength.

Start in a push-up position with the feet on the Swiss ball and hands underneath the shoulders, while the head stays in line with the spine.

Then, activate the deep abdominal wall by drawing the belly button in toward the spine while maintaining a neutral spine position, with the same amount of spinal curvature as you would have standing upright in good posture.

Flatten Your Stomach With a Swiss BallIf you find it challenging to stay in this push-up position and holding your head and back in the correct position, practice staying in this position without moving until you can hold it for 1-2 minutes. Make sure the abs are drawing inward and not pooching out.

To improve core strength, slowly draw your legs up underneath the body. The hips should not rise up into the air (this is not a โ€œpikeโ€). Keep the deep abdominal wall activated and maintain the spine in neutral.

Slowly extend the legs straight to return to the start position. Warm up for 1 set of 6-8 reps, then perform 2-3 sets of 8-10 reps.

Be careful not to use the rectus abdominus to perform the exercise that can result in rounding the trunk. On the other hand, donโ€™t drop the lower back into extension either.

Side Flexion

Flatten Your Stomach With a Swiss BallThis exercise works in the frontal plane, which is often overlooked when training.

Start by lying sideways over the Swiss ball, with the legs split for support. Your feet may be anchored against a wall.

If you’re wanting to improve core stability, side flex up, staying in the frontal plane and hold with good postural alignment for up to 2 minutes.

To increase your core strength, side flex up with your arms across your chest, staying in the frontal plane and slowly return to the start position. Perform 1-2 sets of 6-8 reps.

Want to make this exercise harder? Vary the load (arms to side, arms across chest, fingertips resting by ears, arms extended over the head) or change the lever length. As the ball moves further away from the head, the exercise becomes more difficult.

Two warnings about this exercise:

  1. Make sure not to rotate your trunk as you side flex. Generally, this shows an imbalance between the internal and external obliques.
  1. Take care not to overdo this exercise as the quadratus lumborum can be strained. Your body isn’t accustomed to direct frontal plane loading. Progress slowly and keep the volume low to prevent training injuries!

Once you’ve mastered these exercises, expand your repertoire of Swiss ball exercises by adding the Supine Lateral Ball Roll and Forward Ball Roll.

These are just a small taste of the dozens of exercises that can be performed on a Swiss ball to flatten your abs and strengthen the core. Add them into your current workouts for variety and you may never want to do a crunch again!

Love and chi,