EQUINOX
897 Broadway
212-780-9300

CRUNCH
54 E. 13th St.
212-475-2018

These days, you can work on your samurai skills, your Broadway ambitions, or your Tour de France fantasies in just about any gym—but a basic all-around exercise class (the kind that uses good old-fashioned weights and aerobics and leaves every body part sweaty and shaking) is surprisingly hard to find. Rebounding, as it’s taught by Gregg Cook at Equinox and Louis Muñoz at Crunch, takes place on the mini-trampoline and incorporates sprints, jumps, lunges, punches, and squats, as well as intervals of weights and balance work. The trampoline is a nod to modernity: The “give” protects joints from the jolts of a hardwood floor, while doing the balance and weight work on a wobbly surface gets those all-important core muscles into the game. Some claim that the rhythmic bouncing helps the lymphatic system stay in tune, which keeps colds and flu at bay. And you thought it just warded off the pounds.