I rarely wore these shoes and the laces broke very quickly. The shape and height, increases your center of gravity and makes you more unstable, also making it easier to sprain your ankle, which it caused me to do in a small depression I would otherwise have not. Also, current research shows this kind of "shape up" does not increase any calorie burning compared to normal walking or running, better to get some good fitting regular walkers or runners and walk or run in them!