As a runner this was a must have. Love this shirt. I wear it to run in, hang out in and go out in. It fits beautifully and didn't have a chemical smell as someone else posted. As I own many Raw Threads and have a drawer full, I love the racerbacks the best. I'm 5'2" and wear a 34B or size 2-4 shirt. I own this shirt in Small and XS. The XS is very fitted but not tight which I like when I'm working out. The Small fits just a bit more loser but still fitted. I've noticed the black racerbacks by Raw Threads tend to be a little smaller than the other colors. I bought a blue racerback and it ran a bit bigger and longer than the black one so the colored shirts I always buy a XS but with the black you can't go wrong with Small if your petite like me.