Cardio to arm day, this adidas base layer t-shirt will help you power through. Break your personal records in total comfort thanks to mesh on the upper back, where you need it most, and moisture-absorbing AEROREADY. Everything about this tee is made so you can move freely, like a dynamic shape and super-stretchy fabric.. . . . . Tight fit. Crewneck. 88% recycled polyester, 12% elastane single jersey. Mesh back insert. Moisture-absorbing AEROREADY. Techfit focuses your muscles' energy. Designed for motion. Single jersey. Imported.