These are not ordinary sneakers.  They did seem to make my legs and butt feel a little more sore than normal after walking on the treadmill, so I suspect they might actually help in firming.  However, they make my toes numb!  I couldn't wear them for longer than the walk on the treadmill.  They are very snug around the foot, but the length seemed normal for the size.  Also, the laces are very short.  Overall, I'd buy them only for exercise, not for everyday, and I would not pay full price for them.