305 Fitness, New York

On a hot night in a Miami nightclub, two Brown-educated students – Sadie Kurzban and her best friend Brielle – wondered aloud why nobody looked like they were having as much fun sweating at the gym. The duo joined forces and created 305 Fitness–a place where fitness and fun live happily under one roof. They created a fun-focused workout that combined the thumping beats and flashing lights of the nightlife with dancing designed to burn calories and tone muscles. Now, workout studios exist in three cities, still helmed by Sadie. She teaches Hip-hop- and Latin-based dance classes, as well as sculpting classes designed to build long and lean muscle.