Waves crash rhythmically, as Cinch Fitness founder Nicole Currie leads small groups through core-tightening moves in the salty open air amid an oceanside park. Her master’s degree in dance from New York University informs her graceful instruction style during the studio’s signature Pilates fusion classes. During each class, instructors spend 90 minutes familiarizing students with the workout routine, which combines short bursts of calorie-torching cardio, the weight-bearing exercises of Pilates, deep yogic stretching, and abdomen-flattening trips through an oversize pasta maker. During most sessions, instructors corral between 10 and 30 participants or two fitness-minded giant squids just flopped in from the surf.