I bought this to go under a cheap cotton boxing t-shirt. It does a great job of drawing the sweat out and keeping me cooler in a hot gym. It doesn't ride up or isn't too tight or loose. When I leave boxing I remove my cheap t shirt and just walk to the car in the under armour, it surprising how cold you get instantly, it's great if you can't shower at the gym etc. I bought a Large size, Im about 5'9 with a medium build and I would say the shirt is a good fit.