I've been feeling lethargic and not able to walk fast or with a spring in my step and the Fitflops have helped me walk faster and with more energy. Because of all the padding and shock absorbency they are very comfortable. I gave them three stars instead of four or five because the "gym built-in" claim is an exaggeration. Had they been described as very comfortable shoes that will help induce more walking, which can ad to your fitness level, ok, but so far, I'm not feeling a super tight butt or anything. Also, they're not the best looking shoe I've seen. I paid $60.00 plus shipping & handling which I think is a bit over priced. However, in fairness, they are very comfortable and have helped me walk faster and more comfortably. That's fair, so I do recommend them.