It feels like you're wearing nothing at all, only better, when you work out in the ultralight Women's Fly-By 2.0 Tank Top from Under Armour. This comfortable tank is made from a stretchy fabric that wicks sweat away from you during your workout. Its racerback styling allows freedom of movement, while the flatlock seams eliminate chafing and irritation while you run. If your workout finds you outdoors during low-visibility hours, 360-degree reflectivity lets people know you're there.