Outfits for the active life are all about pieces that are easy to wear with confidence. This adidas by Stella McCartney pick blurs the line between a sports bra and a tank top, letting you take on your workout in a combo of both. It's made with HEAT.RDY technology that is designed to keep you going when things heat up, and laser-cut perforations keep the cool air flowing. The material is buttery soft and perfectly stretchy, giving you the right fit every time. A classic racerback prevents straps from slipping or digging in.