Fitness ball

To do abdominal crunches with the fitness ball:

• Sit on the ball with your feet resting on the floor, about hip-width apart. Keep your back straight. Cross your arms on your chest.
• Tighten your abdominal muscles.
• Lean back, as shown, until you feel the muscles in your midsection tighten. Hold for three deep breaths.
• Return to the starting position and repeat.