I was trying to get by in my training without a belt and felt like I was doing alright, however I was mistaken. A belt, especially a high quality belt, is a must for anyone serious about GS training. I have been using the belt for about 3-4 weeks now and it has been amazing. High quality material, sturdy construction, perfect dimensions, and comfort are what defines this product. I was a bit hesitant to purchase the belt because of the price, however for what you get it is worth it. I cannot speak for other uses, but if you plan on doing GS training then you need a high quality belt to reach peak performance. That is exactly what you get with the 3 layer Kettlebell Sport Belt classic. In regards to sizing I measured out for medium and the belt fit perfectly. This is my first product from Kettlebell Kings and I will definitely be using them again in the future. If you are in the market for a belt go no further!