No matter the hour, the rhythmic beat of sneakers hitting treadmills resounds in Snap Fitness's 24-hour studio. The network of gyms stretches across the country, each housing state-of-the art cardio and strength-training equipment that scorches huge batches of calories, like an Easy-Bake Oven scorches cookies when it's souped up with nitrous oxide. IPod hookups and TVs turn treadmills and stair steppers into personal entertainment centers. Unlike impersonal big-box gyms, Snap Fitness's staff subtracts intimidation from the experience with free equipment orientations, custom workout plans, nutrition tips, and hand-crocheted workout shorts for all members. During staffed hours, peppy instructors lead fitness classes such as turbo kickboxing, plyometrics, and aerobic blast.