The Groupon specials might lure you in the doors of Reforming Pilates, but the topnotch instructors, like Nellie Triana and Estefania Garcia, will keep you coming back. They're all legit masters of Pilates, the muscle-toning, posture-improving, flexibility-boosting workout regimen. Walk up the stairs to the building's laid-back second-floor studio for a challenging one-hour class ($30 drop-in) that will have you exercising muscles you never knew existed. Classes at this cozy studio are conducted on reformer machines, which help Pilates practitioners of all levels stay in proper alignment and form as they work out. With small classes, the passionate instructors are always intently watching, making sure students are performing the exercises correctly — which means you'll get a tight bod in a safe environment. If you can't blast through a class without the right tunes, don't worry: You can always count on Justin, the studio owner, to come prepared with excellent music selections. The studio also offers unlimited monthly classes ($175), a monthly pass for up to 12 classes ($200), and private sessions. Even though this studio is located in Miami Beach, parking is usually easy to come by at the metered lot across the street. Get ready to shake like a leaf.