Assume an elevated, prone plank position – arms and legs extended – while contracting the abdominals and breathing normally. Alternate touching the right hand to the left shoulder and vice versa. Then alternate bring left knee to left outstretched elbow and vice versa. Finally drop the left hip toward the ground, rotate inward, and stretch out the left leg. Return and repeat with the right hip and leg. Try 5 complete circuits, while staying in the elevated plank position.