All American Crossfit, Miami

All American Crossfit co-owner Oscar Castillo is a firefighter, but even though his job is physically demanding, he says it doesn't compare to CrossFit. “What we do at work—it's hard, but it's not as hard as CrossFit,” he says.

But that's not to say the workouts are only for the physically fit—Oscar and his partner can vary the weight and intensity of each exercise for students of any fitness level. The constantly changing workouts combine elements of weightlifting, gymnastics, and cardio to appeal to those who tire of traditional gym routines. Students swing kettlebells, climb ropes, and perfect their Olympic medal acceptance speeches while holding themselves up on gymnastic rings. “It's constantly varied,” Oscar says. “It doesn't get boring.”

As they challenge their bodies with each day's workout, members can draw inspiration from an assortment of colorful flags representing professions such as firefighting, police work, and the military, as well as causes including the fight against breast cancer.