The Base Layer T-Shirt is perfect for the gym or any extreme physical activities. 85% Polyester/15% Spandex blend for a body hugging fit and sweat wicking capabilities. Athletic fit made to show off your form and accentuate your muscle. Raglan sleeves and panel stitching designed to enhance your hard work. If you straddle sizes, go up or down based on what type of fit you are looking for (slightly relaxed, more compressive).