Heart disease grabs headlines, but back pain pesters 80 percent of American women. Exercise is your best defense, a recent Canadian study says. The key: Strengthen, then stretch. Mark Verstegen, author of Core Performance, offers these moves to help.

1) Strengthen: Plate Crunch

Increase Ab strength to help prevent lower back pain, but consult your doctor first. Lie on a Swiss ball, arching back. Hold a 3 to 5 pound plate behind head. Roll hips and chest up simultaneosly, pulling belly in. Crunch, then lower.

2) Stretch: Forearm to Instep Lunge

Step left leg forward in lunge. Place right hand on ground even with the left foot. Touch left elbow down to instep of left foot. Keep back knee up. Move left hand outside left foot and push hips up. Step right foot forward and repeat.

3) Stretch: Russian Twist

Lie with shoulder blades on Swiss ball and hips raised. Keep shoulders back. Extend arms above chest, holding hands together. Keep hips up and turn shoulders to right until perpendicular to fround with hips horizonta. Twist back to center, then to left.