The ab wheel is both a simple and complex exercise device. At first glance, it's just a wheel with a handle through it and grips on both sides. Using it may also appear simple, as you watch exercisers roll the wheel forward and backward. Those movements can be so complicated, however, that only well-conditioned experts can perform some ab wheel exercises, such as full rollouts. Used properly, an ab wheel builds strength in your abs and back, resulting in a solid core.
An ab wheel works the core muscles in your lower torso, including the rectus abdominis in the stomach area, your hip flexors and the latissimus dorsi, which extend across your back from the pelvis to the shoulder. The most basic ab roller exercise, the rollout, works all these muscles. You can also use the ab wheel to work out your arms, shoulders and thighs.
The rollout is the go-to ab wheel exercise for the abdomen and back. Kneel with the wheel at your knees and roll it forward with your hands as far as you can -- preferably until your chest touches the floor -- then roll it back to your knees. Experienced exercisers with very strong abdominal and back muscles can do full rollouts. Start in a standing position with the ab wheel at your feet, roll it forward until your body is parallel to the floor, then roll it back to the starting position.
Leg roll-in exercises work the thighs. Strap the wheel to your ankles with your hands on the floor in a pushup position. Roll the wheel frontward, keeping the legs straight and raising your hips to form a sort of body triangle, then roll back to the starting position. To perform an easier version, pull the wheel forward by bending your knees. This method works the thighs but places less strain on the lower back.
Walk with the ab wheel to work your arms and back. Strap the wheel to your feet, assume a pushup position and walk forward with your hands to strengthen your shoulders and biceps. Perform an alligator walk by walking forward on your hands, while you stop to do a pushup with every step, to hit your upper arms and shoulders. You can also do isometric pushups with your feet strapped to the wheel. Isometric pushups are like regular pushups but with your legs elevated by the wheel to give your arms and shoulders a more intense workout.