If the punching bags that line the workout rooms at Max Combat Fitness could talk, they would probably still keep their mouths shut. That’s how scared they are of the professional and amateur fighters who inflict a beating on them every day during the gym’s muay thai and mixed-martial-arts classes. Led by chiseled combatant George Tsutsui, the team of instructors leads students of all ages and skill levels through the basics of hand-to-hand martial arts. If they aren’t interested in learning MMA strikes or jujitsu grappling techniques, students can burn calories in cardio-kickboxing classes that eschew contact in favor of aerobic dance moves. Similarly, the gym’s conditioning classes improve strength, speed, stamina, and flexibility through stretching exercises and explosive bursts of movement.