We rely on strong core muscles to stabilize the spine and help prevent injuries during everyday activities and sports. This exercise requires your abs to stay tight against the movement of the arms and legs.
Sit upright on a flat, level surface with your knees bent and feet flat on the floor. Place a small, inflatable ball or firm pillow behind your waist. On an exhalation, create a C-curve with your spine, pressing the back of your waist against the ball. Maintain pressure against the ball as you bring your arms out to the sides and rest your hands on the floor. Pause for 2 seconds.
Keeping your abdominal muscles firm, raise your arms in front of your chest and extend your right leg until it's straight. Pause for 3 seconds in this position. Remember to press your navel toward your spine to target your abdominal muscles. Lower your arms and then switch legs. Repeat 12 to 16 times, continuing to alternate legs.
Voight is the creator of a line of fitness DVDs, including "Full Body Stretch" and "Ballet BodySculpt."