New workouts pop up every day, and wouldn’t it be nice to try before you buy? In our “Last Night’s Workout” series we sweat, stretch and shimmy our way through the latest exercise crazes and report back to you so you can find the best one for your skill level and fitness goals.The workout: A FitWalker machine is basically a treadmill without a motor. To get the belt going, you have to rev it up with your legs, and if you slow down or stop moving, you have to get it started all over again—which makes it a killer workout for your thighs. You can also control the belt’s resistance with a dial, similarly to a spin bike. (But if it takes all your body weight to get that belt to move like it did for us, you should stick to the least resistance your first few times.) Although the machine mimics a treadmill, there’s little running during the hour-long class. A combination of moves that take you sideways, stepping down off the FitWalker, back onto it and then off onto the other side (all while keeping the belt in motion) will leave you gasping for air and feeling naïve for thinking the FitWalker looked harmless.Christian Castano, a personal trainer at Superstar Gym, leads the classes, which debuted summer 2013. But the FitWalker was actually invented a couple of years ago in Italy. “People started to get bored with spinning classes because spinning offers one dimensional, monotone movement,” Castano says. “Fitwalker came as an alternative, offering a variety of moves and unlimited numbers of workouts.” To make the class his own, Castano has implemented some of the moves they use in Italy while also inventing new ones. Those moves include leg lifts, squats, jogging, and lateral and backwards walking, as well as side crunches and push-ups. Some also involve ramping up the incline to boost the intensity. To further hold onto its Euro roots, the class soundtrack is packed with upbeat electronic tunes.The goal: A whole body workout combining fun moves and heart-pumping cardio. “FitWalker offers variety and brings fun to the workout,” Castano says. “Each class is designed differently—some are more focused on core and performance and others are a mixture of dance, yoga, barre, pilates and cardio moves,” he adds, so you’ll never be bored, even if you keep going back for more classes.The location: Superstar Gym, in the TriBeCa neighborhood of New York City, is the first facility to bring these machines stateside. We’re told that soon these machines will be in gyms across the U.S., giving those outside of the NYC area the opportunity to participate.The price: Classes are $30 each, and you don’t have to be a gym member to take one. They’re offered every weekday at 7:30 a.m. and 7 p.m. and on the weekends at 9 a.m. and 2 p.m., and you can sign up online here.