Today, it's undeniable: Jazzercise is a worldwide empire, spanning more than 1,800 locations and 32,000 weekly classes across the globe. It's also hip; gone are the leotards and legwarmers of the 1980s, replaced with a high-intensity blend of cardio, strength training, kickboxing and power yoga performed to hits by chart-toppers from Shakira to Justin Timberlake. The class formats, which vary according to different toning goals, are just as diverse as the program's move set, with recent additions such as Fusion, Core, and Strike broadening the workouts' variety and application. Instructors cultivate a noncompetitive atmosphere where all exercisers are welcome regardless of age, build, or fitness background. This sense of community keeps Jazzercise devotees coming back, but so too do the results; benefits ranging from weight loss and boosted core strength to increased flexibility and stress relief.