Ab machines strengthen your lower, upper and oblique abdominal muscles. Ab crunch machine also involves high intensity muscular overload. It is therefore necessary to protect your back, neck, head, and upper body when doing ab exercises. The Ab trainer or the ab workout machine is designed to help you protect the rest of your body while strengthening and toning your abs. The ab exercise machine helps you achieve the kind of abs that you want without too much strain. Check out our collection of the best ab machines.