Update: I originally ordered a Large sized knee brace, but it was too loose and did not compress so I returned it. That same week, I was contacted by Frank from the BERTER customer service team. He was very friendly and offered to send me the medium sized knee brace to try. I am happy to report that the medium fits perfectly and I couldn't be happier! The fabric breathes really well so this brace is great for working out. I have used it for circuit training and pilates, and it's flexible enough See full review