this dress runs quite small...I ordered small first as I always wear small for Nike, but I even had difficulty putting this on. I tried Medium, still very tight, and the pink strap doesn't even sit on your waste properly, more like on rib cage. The top part fabric is very stretchy and clingy, combining with the tight waist my upper torso looks like sausage filling. Sorry, not for me.
As the other person said, it is very tight around the band although it is very stretchy. Also, I am high waisted so the band sits around my rib cage. Something you have to keep in mind.