Crunch Fitness, San Francisco

Though now spread over the United States, Crunch gym started in a basement-level aerobics studio in New York City. Despite the humble location, the gym's founders aspired to foster a workout environment that would keep members exercising through entertainment and not shouting from drill-sergeant-like trainers. Their idea was to host fitness classes with offbeat touches, including hip-hop aerobics featuring a live rapper and coed action wrestling.

Twenty years later, Crunch gyms' fitness classes still stray from the beaten path. Body Web with TRX sessions suspend members from a pillar, where they complete gravity-defying maneuvers with help from strong resistance ropes. In Bosu Bootcamp, every exercise is completed on an apparatus that is part balance ball, part core board, and fully endorsed by circus seals nationwide.