Got aggressions that need to be worked out? Love heavy music? Wanna be as lean as Tommy Lee? Kirsten Potenza and Cristina Peerenboom, who love drumming, dance and fitness, have developed what may be the next major phenomenon in exercise: Pound. Slamming drumsticks into the floor as hard as you can while doing specially tailored Pilates and cardio routines might seem like raucous fun, but this is no “get physical” fad. The gals have developed special resin sticks (“ripstix”) that provide resistance that goes beyond wood. The room takes on a primal, almost hypnotic feel when everyone is pounding in unison. There are no self-conscious leg-warmer types here, either. The instructors wear faded rock tees and Chucks. The classes are packed and very loud (some participants wear earplugs). If it sounds like the pit at a rock concert, it kinda is — especially the post-show euphoria part. Only here, you're the rock star. Classes are currently available at local Crunch Fitness locations. poundfit.com.