You've got your rotation of cute workout leggings on lock, and now, there's nothing left but to complete your 'fit with a breezy tank top to stay cool yet covered up while you continue to sweat it out from your living room . And while you may already have a couple of go-to sleep tanks subbing in as a wardrobe placeholder, we're making the case for picking up fitness-geared ones that are made with moisture-wicking in mind.