Sunlight streams in through the floor-to-ceiling windows, bathing Erin Haag, her troupe of Power Pilates–certified instructors, and small-group exercisers in light as they tone cores and build muscle on the black Reformer machines. Pilates of Palm Beach’s titular Pilates classes stay true to Joseph Pilates’s six foundational principles, including focusing on executing each exercise with complete muscular control, initiating movements from your core, and paying complete attention to the exercise and nothing else, not even the gorilla in the middle of the room. Instructors also complement the Pilates classes with more peaceful yoga classes.