Bright-yellow spheres hurtle through the air like comets in space or butter pats in a food fight. Unlike comets or butter, however, these objects can be whacked with a racket on Intensity's seven indoor tennis courts. Here, adults and kids learn to volley with precision during clinics, camps, and team programs. Accomplished tennis pros lead one-on-one lessons for students of all levels and a high-performance academy for elite young players. During Turbo Tennis sessions, instructors pair forehands and backhands with endurance exercises to help players sculpt their physiques and up their game.

Dance, yoga, and biking tone muscles and melt calories during many of Intensity's other fitness classes. Latin-inspired Zumba workouts boost energy levels in a 3,000-square-foot studio whose booming beats and intelligent lighting system simulate a thriving nightclub or a disco aboard a flying saucer. Octane elliptical machines, True treadmills, and Life Fitness strength-training equipment fuel solo workouts in the studio's gym, and a four-lane 100-foot track helps athletes sprint their way toward optimal speed and agility.

After workouts, exercisers may unwind with Thai massages, respites in the onsite saunas, and trips to the juice bar. Childcare staff can supervise kids 12 weeks and older while parents exercise, work, or run errands.