You don’t need a sparring partner to whoop ass! Swinging, hooking and jabbing (shadow boxing) is a total-body workout too. “Your arms, legs and core are working to propel each rotation,” says fitness instructor Christa DiPaolo, creator of the boxing-based class The Cut at Equinox. “As long as you’re moving quickly, you’re going to get your heart pumping, fire up your major muscles and blast calories.”