yep. i tested it in real life too, on my roomie with his shirt up. when twisting to the left or right, your stomach/abdomen doesn't really move all that much, its mostly in your chest. this of course would vary from person to person, depending on how flexible you are, as to how far you can twist, but still the movement is mostly in the chest/upper torso. plus, he's an anatomy major. 8-) E.D.