Ball Obliques Exercises

The body's core contains four layers: the external and internal obliques, the rectus abdominis and transverse abdominis, which is the innermost layer. Exercisers most often target the rectus abdominis, or the "six pack," during workouts. On the stability ball, the transverse abdominis engages in an effort to maintain balance. During your workouts, target the layers of oblique muscles, which lay on either side of the rectus abdominis, to better increase their strength and flexibility.

Oblique Twist

The oblique twist is a basic ball exercise that engages all four abdominal layers, with specific emphasis on the oblique muscles. The exercise also increases spinal mobility. Sit on the ball with your feet flat on the floor, hip-width apart. Walk your feet so you can roll onto your back. Your heels should be directly under your knees, and your trunk -- not your shoulders -- should rest on top of the ball. Cross your arms over your chest, bringing each hand to the opposite shoulder. Keep your hands relaxed to prevent the urge to assist your upper body. Drop your navel toward your spine. Activate your abdominal muscles and lift your trunk up toward the opposite wall. As you lift, simultaneously rotate your left ribcage toward your right hip. Pause before returning to the start position with full control. Repeat the exercise, alternating sides.

Side Crunch

While side crunches also use all of the abdominal muscles, the oblique muscles are the primary movers for the exercise. Perform the movement with a mat under the ball to cushion your knees. Kneel with the ball close to your right side. Lean into it, placing your right arm across the top to stabilize your body and keep the ball from rolling away. Extend your left leg out to the side, connecting to the floor on the inside of your foot, without bending your ankle. The left side of your body should be a long line from your head to your foot. Place your left hand behind your head, keeping your elbow wide. Engage your abdominals as you bring your left ribcage toward your left hip. Perform 10 to 15 repetitions on one side before switching to the other side.

Knee Tuck

The knee tuck is an advance ball exercise requiring full abdominal engagement and control. Knee tucks also work the rest of the abdominal muscles, the quadriceps, the gluteal muscles, the deltoids, the triceps and the pectoral muscles. Lie on your stomach over the top of the ball with your toes and hands touching the floor on either side. Keep your feet hip-width apart and your hands directly under your shoulders. Engage your abdominals and walk yourself forward on your hands until the ball rests until your shins or feet. The further away it is from your center, the harder it is to control. Keep your arms straight and press your legs together, activating your glutes. Tuck your knees into your chest, allowing the ball to roll forward. Initiate the movement from your abdomen. Release the tuck by extending your legs. On the next movement, bring your knees toward your left arm. Extend your legs and tuck toward your right arm. Alternate side-center-side for as many repetitions as you can perform in 90 seconds.