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

Promoted as a fitness philosophy as well as a competitive sport, CrossFit workouts CrossFit incorporate elements of high-intensity interval training, Olympic weightlifting, plyometrics, weightlifting, gymnastics, gyrophysics, calisthenics, strongman, and other exercises.

It is practiced by members of more than 13,000 affiliated gyms, about half of which are in the United States, and by individuals who complete daily workouts (also known as "WODs" or "workouts of the day").

CrossFit has come into some controversy for allegedly causing people to suffer unnecessary injury and exertional rhabdomyolysis, a condition in which muscle tissues die.

CrossFit is a strength and conditioning program that consists primarily of a combination of aerobic exercise, calisthenics (bodyweight exercises), and Olympic weightlifting. CrossFit, Inc. Descriptionribes its strength and conditioning program as "constantly varied functional movements executed at high intensity in broad time and modal domains," with the stated goal of improving physical fitness, which it defines as "ability to work over time." of time and modal domains.