Though they're all in enviable shape, you shouldn't feel intimidated by the highly accomplished certified trainers at Castle Hills CrossFit. The team—which includes pro fitness competitors, marathon runners, and Tae Kwon Do black belts amongst its ranks— works hard to foster an encouraging atmosphere in the gym, motivating patrons of all ages and fitness levels to work together to tackle the workout of the day.

But that doesn't mean the sessions are easy. Each day, the trainers lead a routine that combines interval, strength, cardio, and flexibility training into one high-intensity, functional workout. And no two workouts are the same. One day, it might incorporate kettlebell drills and TRX band exercises, while the next might challenge patrons to toss medicine balls or heave bags of sand. Meanwhile, those who prefer to exercise at their own pace can gain 24-hour access to top-of-the-line fitness equipment, including cardio machines equipped with personal TVs that always remember your name.