You can definitely feel it doing something, especially on the higher settings, but it's hard to say if it actually works. The big issue is the pads have a pretty short life span, even if you use the extra gel they give you, keep them in the zip lock bags, and all the other stuff they tell you. I didn't count exactly how many uses, but it was less than the 20-30 they advertise, and then it's about $15 for new ones. Overall I think it's an easy way to strengthen your core, but I wouldn't expect itSee full review