Primarily, it’s a fitness regimen developed by Coach Greg Glassman over several decades. As the first person in history to define fitness in a meaningful, measurable way (increased work capacity across broad time and modal domains). CrossFit itself is defined as that which optimises fitness (constantly varied functional movements performed at relatively high intensity). CrossFit is also the community that spontaneously arises when people do these workouts together. In fact, the communal aspect of CrossFit is a key component of why it’s so effective.
Today, CrossFit the company, provides accredited training seminars throughout the world. They publish several websites providing extensive free content, including workouts, training and support for becoming fit, as well as a growing Journal of extended instruction. They have a worldwide network of more than 5,500 affiliated gyms and more than 35,000 accredited CrossFit Level 1 trainers. And they have created the Sport of Fitness, known as the CrossFit Games, where they crown the Fittest Man and Woman on Earth!