Primary Muscle Group: Internal and External Obliques
Muscle groups worked in this exercise:
Preparation: Lie on the floor on your back with knees bent and place both heels on the ball. Now, interlace your fingers behind your head and make sure your elbows are out to the sides.
Execution: Exhale as you lift your right shoulder toward your left hip. Go back to start and then switch sides. Watch that ball, as it has a tendency to roll away from you so hold it tightly in place with your leg muscles.
Comments: If you're not quite ready to advance to the oblique twist, this is a great option until you can.