If you're not into martial arts, you may well have despaired of ever getting a chance to strap on boxing gloves and beat on a punching bag to the sound of music. But Cuong Nhu's kickboxing class offers an intense 60-minute workout and a chance to pound a punching bag until you can barely stand. The class caters to folks who aren't interested in the endless minutiae of ordinary martial arts classes -- sure, there are a few pointers on technique, but not so many that it will get on your nerves. And because there's not much emphasis on form, the class works for novices and martial arts veterans alike. It's offered most weekday evenings, and once you try it, you might never climb simulated stairs again.