No es eficiente.Was expecting better quality for the price and for a neoprene material but it’s light and still makes you sweat, which is what matters. I should have gone a size smaller but will work for now. I purchased a size medium, I’m 5’4” 150 lbs.no me agradoI love this waist trainer. My tummy area has ALWAYS been my issue. I started wearing the Hot Shapers waist cincher to my kickboxing classes. 1. Thought it would limit my mobility when having to kick and box. It takes a second to get use to the feeling of something hugging you, but after you do it moves along with your body when exercising. 2. Kickboxing makes me sweat already, but with the waist cinched, I worked up swear doubletime and especially around my tummy 3. I wear it under clothes even when I'm not working out :) It holds my tummy in and just makes me look sexier with it on! 4. The sizes were true to size. If you look on the size chart, it was very accurate for me.So I received it and the fabric is stretchy but I guess the belt is supposed to snatch your waist and make it tight. However, I do not believe that it is supposed to roll up on the side and back. It hurt my back. I was disappointed because I did have the right measurements but felt it was not correct fit.I am not happy with this purchase. While the vest portion fit well, the belt was disproportionately tight. I tried to wear the item out for a run but the bottom portion kept on rolling up (which was incredibly annoying). The item is otherwise of good quality and made with good material. I guess it works for some but it sadly did not work for me.I bought this product for back support and posture. It's perfect and excellent material. ? I will buy it again.Muy buena inversiónFaja muy ligera y cómoda, cumple con todos los requisitos