If you're the type of person who doesn't feel satisfied with a workout unless you're sore the next day, you need to check out the latest fitness trend: The Lagree Fitness Method has been big in California for a few years now, but it's just now sweeping the country; it's currently offered at more than 100 studios across America, and more locations are in the works.

Founder Sebastien Lagree developed the workouts in Los Angeles after he noticed how many of his clients were hitting the treadmill directly after their Pilates sessions. "I told them, 'If you want cardio, I can give you a Pilates workout that gets your heart rate up,'" he says. Eventually, he even approached engineers about designing an amped up version of a reformer that comes with added bells and whistles to give you an even better workout. "There are platforms at both the front and back of the machine, and it has lots of attachments so you can do more with it and hit more muscles," says Tracy Carlinsky, owner of Brooklyn BodyBurn located in Brooklyn, NY, one of the newest studios to offer The Lagree Fitness Method.

The classes can last anywhere from 25 to 50 minutes, and each movement is designed to be completed as slowly as possible, working muscles past the point of exhaustion so you'll see quick results. "People call it Pilates on crack," says Carlinsky. "I was hooked from the first time I went, which is why I had to open my own studio when I moved to the East Coast." Lagree estimates that an average-sized woman can burn more than 700 calories in a 50-minute class—so you don't have to spend a ton of time at the gym to totally transform your body.