If the closest you've come to a boxing ring is drooling over Jake Gyllenhaal's biceps in Southpaw, it's time to give your upper body a little TLC. The latest heavy-bag boxing classes incorporate a muscle-building mix of plyometrics and shadowboxing (don't worry, there's no contact, so experience isn't needed). Each class is split between punching and crunching, so be sure to choose loose-fitting apparel that allows you to quickly switch positions, says Caroline Gogolak, founder of fitness platform Carbon 38. According to Gogolak, you'll want to look for "a supportive waistband that won't ride down when you're doing your high kicks and a sports bra [that] carries enough support, so you're ready for combat."
Try It at a Studio
Boutique studios like The Boxing Gym in St. Louis, Gloveworx in Santa Monica, and Shadowbox in N.Y.C. offer hands-on training through group workout classes and private, one-on-one training.
Try It at Home
Stream step-by-step videos of beginner combinations and pro punching tips from the Boxercise app (free; apple.itunes.com). In a rush? Follow along with quickie 15-minute toning workouts. The app syncs with your favorite playlists so you can keep pace with your music.