While this ab exercise mainly targets your obliques, your back muscles will be engaged to strengthen and support your spine. To increase the difficulty of this exercise, hold a five-pound medicine ball or dumbbell at chest height:
- Sit on the ground with your knees bent and your heels about a foot from your bum.
- Lean slightly back without rounding your spine at all. It is really important, and difficult, to keep your back straight, but don’t let it curve.
- Place your arms straight out in front of you with your hands one on top of the other. Your hands should be level with the bottom of your rib cage.
- Pull your navel to your spine and twist slowly to the left. The movement is not large and comes from the ribs rotating, not from your arms swinging. Inhale through center and rotate to the right. This completes one rep.
- Do 16 full rotations.