As Medford said, a ab wheel at Wal-Mart is a very good investment. It will hit the upper & lower ab wall, as well as the obliques. Some people will have trouble with their lower back on these because they extend all the way down to the floor (face almost touching), don't have to do that to get the full rewards from the ab wheel. Might want to spray some WD-40 (or whatever) on the inside of the wheel for a smoother action. Though some people think these are just toy's, they would be mistaken. Once you get use to the exercise, say 20 reps or so, you can start with your toes on a bench/chair. Can also start standing and bending over and doing something like a J Knife exercise. Good Luck.