If sleeves cramp your workout vibe, keep things streamlined and go for a tank top instead. The racerback design of this adidas top leaves the shoulders wide open for uninterrupted range of motion. You'll appreciate that gust of air against your skin, whether it's coming from that metal fan propped up above the treadmill or a crisp breeze on the trail. Racerback. Round neck. 64% recycled polyester, 36% polyester single jersey. Racerback sleeveless t-shirt. Moisture-absorbing AEROREADY.