I have worn these three times now while running and working out. I am a 34 A and the smalls fit me well. I had a problem with other sports bras that were too big and didn't provide enough snug support. These are nice and tight. The cup inserts look a bit silly so I removed them all, but if you are looking to pick someone up in the gym, they might do the trick, haha.

Only downside, which another reviewer mentioned, is that they can scratch a bit on your arm, but once pulled down and in place I didn't have any trouble. I also think it depends on what type of shirt you wear over them, as some of my shirts cover the bra entirely.