CrossFit Combat Fitness coaches, armed with degrees in kinesiology and exercise science, lead workouts designed to enhance their clients’ agility, endurance, and speed inside a 2,100-square-foot facility. Each session focuses on different exercises; sometimes participants toss 20-pound balls, sometimes they flip giant tractor tires, haul 80-pound kegs, or spring from a standstill to leap atop stacked plyo boxes. Coaches customize workouts so participants are asked to do only what they can physically handle. Classes are scheduled five days a week, and on off days athletes can hit the open gym or stay home and read the dictionary, whichever they prefer.