If you're into the smushed-boobies-effect then go for it. I usually take a medium or small in almost all work-out type clothing. I ordered this in a medium and it was so tight I was spilling out from the sides and back. yuck. no back-fat here! i detest that look.  thing is, i felt that if i exchanged it for a large i'd be swimming in it and would lose the whole purpose of support. So, it just didn't fit right and was not flattering on me. Maybe for someone, but not me. (34B, 120 lbs)