CrossFit

CrossFit is a branded fitness regimen that involves constantly varied functional movements performed at high intensity. The method was developed by Greg Glassman, who founded CrossFit with Lauren Jenai in 2000, with CrossFit as its registered trademark. The company forms what has been described as the biggest fitness chain in the world, with around 10,000 affiliated gyms in over 150 countries as of 2025, about 40% of which are located in the United States. CrossFit is promoted as both a physical exercise philosophy and a competitive fitness sport, incorporating elements from high-intensity interval training (HIIT), Olympic weightlifting, plyometrics, powerlifting, gymnastics, kettlebell lifting, calisthenics, strongman, and other exercises. CrossFit presents its training program as one that can best prepare its trainees for any physical contingency, preparing them for what may be "unknown" and "unknowable". It is practiced by members in CrossFit-affiliated gyms, and by individuals who complete daily workouts (otherwise known as "WODs" or "Workouts of the Day"). Studies indicate that CrossFit can have positive effects on a number of physical fitness parameters and body composition, as well as on the mental state and social life of its participants. CrossFit has been criticized for causing more injuries than other sporting activities such as weightlifting, although a review article in the Journal of Sports Rehabilitation found that "the risk of injury from participation in CrossFit is comparable to or lower than some common forms of exercise or strength training". Its health benefits and injury rates are determined to be similar to other exercise programs. There are also concerns that its methodology may cause exertional rhabdomyolysis, a possible life-threatening condition also found in other sports, resulting from a breakdown of muscle from extreme exertion.