I am 55 and 170 pounds I got a large because my waist was around 34 inches. I was a litttle worried that it would be too uncomfortable. I was surprised to find that its was not. Its actually really good because it has a little give in it and would be great for some working out. I do taekwondo and I would not be able to do it in this. I don't have the same flexibility. But for the gym it would work great. I moved to the tightest fit in only a few days but its more likely because I have 27% body fat and it is more likely just squeezing in the fat. Will be buying a smaller size to keep going smaller.