Within the expansive, red-floor studio, groups of boot campers huff and puff during intense, 45-minute sessions designed specifically to burn off weight. Certified personal trainers and profoundly confused lion tamers roam the floor, leading exercisers through strength training with kettlebells and heavy ropes to amp up muscles, and interval cardio that gets rid of calories. A suite of 21 morning classes a week fits nicely into busy schedules. For more focused attention, personal coaches take clients under their rippling wings, creating menu plans, taking measurements, and giving out personal email addresses and phone numbers.