don't size up!
I tried these on last year when I wasn't considering buying them, and didn't have much patience for fighting to get them on in the dressing room. So I got them as a gift, unfortunately in a size too big (M) for my 5'4" and 125 lb frame. They are fun to run in, and I do feel a bit more energetic than otherwise. They aren't very warm but they keep your body temp averaged out nicely once you get warm. With them being too big, I have bunching behind the knees and unfortunately the crotch went down about 2 inches as I ran, I had to roll the waist and tie them across my hips. Probably better compression if they fit right...