CrossFit is a strength and conditioning brand that combines weightlifting, sprinting, gymnastics, powerlifting, kettlebell training, plyometrics, rowing, and medicine ball training.  CrossFit contends that a healthy, fit person requires proficiency in each of ten general physical skills cardiovascular/respiratory endurance, stamina, strength, flexibility, power, speed, agility, balance, coordination, and accuracy.  CrossFit athletes run, row, jump rope, climb rope and carry odd objects. They frequently move large loads quickly over short distances, and use powerlifting and Olympic weightlifting techniques. CrossFit athletes also use dumbbells, gymnastics rings, pull-up bars, kettlebells, and many bodyweight exercises. CrossFit is the principal strength and conditioning program for many police academies and tactical operations teams, military special operations units, champion martial artists, and hundreds of other elite and professional athletes worldwide