A ball adds punch to the crunch

When you want to challenge your abdominal muscles and kick up the intensity of your workout, try doing your crunches on a large stability ball. It will train your abs to use strength, control and balance with every crunch.

1. Sit on top of a stability ball. Walk your feet forward away from the ball and position your middle to lower back on the top of the ball. Place your feet flat on the floor, hip-width apart. Your knees should be over your ankles and your thighs parallel to the floor. Place your hands behind your head. Lie back so your upper body is extended over the ball. Inhale.

2. On the exhale, contract your abdominals by pulling your navel toward your spine. Curl forward, bringing your chest and ribs toward your hips. Hold the peak of the contraction for two beats and slowly lower your upper body back to the ball. Repeat 16 to 20 times, rest for 30 seconds and repeat for two more sets.