Muscles worked: Midsection (obliques, abs) How to do it: Sit on the floor with your knees bent and feet about six inches off the floor (for a modification, keep feet flat on floor) and lean back slightly. Begin by rotating your torso to one side and then rotate directly to the other side. Continue rotating side to side without stopping in the middle. Make sure your chest is lifted and back is straight. Tips: Keep abdominals tight -- as if preparing for a blow to the stomach. Start by holding a light medicine ball or weight and work up to a heavier weight as you get stronger. Be careful if you have lower back problems; if you feel back pain don't do this exercise.
Sarah Pastrana, Baltimore Sun Media Group