CrossFit is a branded fitness regimen created by Greg Glassman. It is a registered trademark of CrossFit, Inc., which was founded by Glassman and Lauren Jenai in 2000. 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 over 13,000 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.