Abdominal Ball Twist Exercises

Abdominal twist exercises with an ab ball can be done in a variety of positions, including seated on a ball, lying on a ball or holding a ball. Twisting exercises strengthen your internal and external obliques. These muscles have four main jobs: to rotate your upper body, bend your upper body sideways, flex your spine and compress your stomach to support your spine. Using the ball and twisting guarantees that your obliques will work to stabilize and rotate your spine.

Side Twist

The side twist exercise works your obliques as you sit on a ball and rotate your upper body, says Jeanine Detz in her "Ultimate Core Ball Workout" book. The side twist exercise depends on keeping your hip and lower body still when performing the twisting motion so the obliques are isolated. Begin seated on a ball with your knees bent at right angles and your feet on the floor. Sit up straight and lift your arms straight out to your sides with your palms facing down. Twist your upper body and look right. Then, twist back to the starting position. Twist to the left and back to complete the exercise.

Oblique Crunch with Feet on Ball

This exercise requires you to twist your upper body while your lower body stays stable even though your lower legs are on a ball. Preventing the ball, your legs or your hips from moving challenges all of the ab muscles. Begin by lying face up on the floor with your knees bent and your lower legs on top of the ball. Support your neck with your arms. Then, raise your head and shoulders. As soon as you've lifted your shoulders off the floor, twist to one side in a fluid motion, recommends Detz. Do not make these separate movements. Return to the floor before lifting and twisting in the opposite direction.

Ball Crunch with Twist

The ball crunch with twist is done lying with your back on the ball and your feet on the floor with the knees bent. All of your abdominal muscles work together to stabilize your torso on the ball, flex your spine as you crunch upward and twist your upper body. Lie on the ball and place your hands behind your head. Position the ball under your lower back with your shoulders and head clear. Squeeze your abs and sit up. Once you have reached the upright seated position, twist your upper body to bring your right elbow toward your left knee. Lie back down to the starting position. On the next rep, twist your upper body the other way to bring your left elbow toward your right knee.