Knockout Fitness, Goodyear

Knockout Fitness's instructors lead one-hour, kickboxing-inspired workout routines. They keep classes small, guiding students first through warm-ups and then stretching routines. Then, they hit the bags, quite literally. Each student squares off against a 150-pound heavy bag or an instructor holding pads, practicing fast-paced striking sequences that help build speed, strength, and endurance. Teachers incorporate ab exercises along the way and lead a cool down that's just as important as the warm-up.

Though fitness classes comprise a lot of what they do, the trainers also teach martial arts classes. In addition to boxing and kickboxing sessions, they lead jiu-jitsu training and MMA classes, where athletes mix all their skills together in one match. Every class focuses on developing technique and endurance, and many guests choose to supplement their training with the gym's weight-lifting focused programs, especially if they plan on fighting a barbell.