I should have gotten a size bigger. I'm 5'9" and have a large athletic build (i'm a rower). I ordered a Large. I got these for running and rowing in cold weather. Although the fact they are so tight is very flattering, within a couple months the crotch of my tights busted.They are also short, inches above the ankle short. I've been compromising for months now but have recently decided to see if CW-X will take them back under warranty... I want a new pair though, they're awesome!