CrossFit is...
...constantly varied, functional movement, at high intensity.
Gymnastics
Weightlifting
Conditioning
The Methodology
You've probably seen a professional athlete on TV or a magazine and thought, "wow that person looks fit." Prior to CrossFit there was no formal definition of fitness -- It was one of those you-know-it-when-you-see-it type things.
CrossFit changed this by providing a clear and complete definition of fitness:
"work capacity across broad time and modal domains"
This means your ability to move a variety of objects in different environments.
Under this definition fitness became observable, measurable, and repeatable. CrossFit provided a way to evaluate increases and/or decreases in a person's fitness.
The goal of CrossFit is to increase your work capacity across broad time and modal domains. To increase your fitness.
The Community
But at the end of the day, CrossFit is entirely about the community. You will share an emotional journey with your sisters and brothers. We all support each other because we are all working to better ourselves in a shared struggle every day. It becomes a way of life.
*Courtesy of CrossFit, Inc.
Nutrition
Eat meats and vegetables, nuts and seeds, some fruit, little starch, and no sugar.
Athlete
The pyramid below is CrossFit's theoretical development of an athlete. The image is courtesy of CrossFit, Inc. and you can read more about it here.