CrossFit's official definition is constantly varied, functional movement, performed at high intensity. Routine is the enemy! We must be ready for the known and unknowable.
Combining the CrossFit training methodology with a diet of meat and vegetables, nuts and seeds, some fruit, little starch and no sugar brings "a jet stream of adaptation," says CrossFit founder Greg Glassman. In the pyramid Glassman created, nutrition is the foundation, with met-cons, gymnastics, weightlifting and throwing, and sport following.
Functional Movements are what prepare you for life.