 CrossFit is promoted as both a physical exercise philosophy and a competitive fitness sport, incorporating elements from high-intensity interval training, Olympic weightlifting, plyometrics, powerlifting, gymnastics, girevoy sport, calisthenics, strongman, and other exercises.It is practiced by members of thousands of affiliated gyms, roughly half of which are located in the United States, and by individuals who complete daily workouts (otherwise known as "WODs" or "workouts of the day").CrossFit has been criticized for allegedly causing people to suffer from unnecessary injuries and exertional rhabdomyolysis, a possible life-threatening breakdown of muscle from extreme exertion.