Fitness Defined

In his revolutionary 2002 article titled "What is Fitness", Greg Glassman assigned a measurable and actionable definition of "Fitness" for the first time in history, clearly breaking down the rationale behind it. CrossFit introduced three different standards or models for fitness measurement in 2002.

The First Fitness Standard posited by CrossFit is that an athlete is only as fit as he/she is competent in each of the ten general physical skills pictured above. Athletes can secure improvements in endurance, stamina, strength, and flexibility through Training. Practice improves coordination, agility, balance, and accuracy. Power and speed adaptations result from a mixture of both training and practice. Training improves performance through organic changes in the body; practice improves performance through nervous system modifications.

The Second Fitness Standard CrossFit posits, that the fittest athlete can perform best across an number of randomly-drawn challenges (of infinite possibility), compared to all competitors. Winning all events is not a requirement. Being the most consistently at, or near, the top is a requirement. This fitness standard is what brings emphasis to a broad, general, and constantly varied training stimulus. Life, being unpredictable, is confronted optimally with a both broad and general Fitness regimen. CrossFit can therefore claim "our specialty is not specializing". This is referred to as CrossFit's "Hopper Model". 

CrossFit's proposed Third Fitness Standard requires the athlete to have competency and training in each of three metabolic pathways: the phosphagen pathway, the glycolytic pathway and the oxidative pathway. It measures power in relation to time. CrossFit declares that two of the most common faults in fitness training are "favoring one or two to the exclusion of the others, and not recognizing the impact of excessive training in the oxidative pathway"

Through these operational fitness standards, CrossFit prioritizes "broad, general, and inclusive" Fitness.

A Fourth Model brings a definition of Health onto a continuum with Fitness where "Wellness" must be passed prior to "Sickness" experience. Greg Glassman explained: "Done right, fitness provides a great margin of protection against the ravages of time and disease".

Fitness is a Buffer against Decrepitude

Knowing where you fall on the Sickness/Wellness Continuum can help you calculate the urgency with which you should invest attention on optimizing nutrition, sleep quality, stress-management and fitness training in addition to other lifestyle variables. Combined objective measurements including but not limited to Blood Pressure, Hip/Waist Ratio, Body Fat, Bone Density, Triglyceride Level, HDL Cholesterol Level, Flexibility, Muscle Mass, and the presence/absence of chronic disease including Depression and Type II Diabetes triangulate your approximate position on a continuum which extends from "Likelihood of Early &Painful Death" to "Optimal Living". Your ability to track your own progress between the two extremes puts you squarely in the Driver's Seat where you are less likely to be tempted to Outsource your Health. Critically, according to CrossFit way back in 2002: "A fitness regimen that doesn't support health is not CrossFit".

In 2009, Greg Glassman updated his Fitness definition, intimately linking the Fitness and Health fields using a Three-Dimensional Model integrating age: "Increased Work Capacity Across Broad Time, Modal, and Age Domains". He stressed the importance of measurable, observable, repeatable data using kinematics in the science of human performance. We measure work capacity by average power (Force x Distance / Time).

Coach Glassman explained that Fitness can be defined as the ability to move large loads, long distances, quickly, and in the broadest variety of domains. CrossFit contends Fitness is achieved most efficaciously through "constantly varied high intensity functional movements".

The first three fitness standards can be united by a Work Capacity Graph (with the x-axis showing increasing duration of effort, and power on the y-axis), and the area under the curve will then provide us with a Precise Measure of Fitness. A third z-axis for age, makes this Work Capacity Graph 3-dimensional, and emphasizes the importance of Sustained Fitness over Life by making it finally Quantifiable. Health is nothing other than the ability to sustain Fitness over life. Coach Glassman explained that the Sickness/Wellness continuum therefore becomes controlled by an athlete's ability to maximize the volume of work capacity across broad time and modal domains throughout his/her life.

Why Definitions Matter

Now that Fitness and Health are clearly defined, we can measure and rate any fitness or health protocol against this standard. We can determine the merit of any known fitness program by its efficacy in securing improvements in these precisely defined Fitness and Health Standards over time and for the athlete's life. A program's merit then becomes not only measurable, but also contrastable to its competition.

And laying claim to not only the first but also the most efficacious definition of Fitness, allows CrossFit to crown its fittest athletes legitimately "The Fittest On Earth".

CrossFit didn't just start focusing on Health in 2019 with the launch of the CrossFit Health website; its emphasis has always been there. Read more about CrossFit's vision of how Health and Fitness are forever intertwined here.

Greg Glassman summarizes World-Class Fitness in 100 Words:

Eat meat and vegetables, nuts and seeds, some fruit, little starch and no sugar. Keep intake to levels that will support exercise but not body fat. ■ Practice and train major lifts: Deadlift, clean, squat, presses, C&J, and snatch. Similarly, master the basics of gymnastics: pull-ups, dips, rope climb, push-ups, sit-ups, presses to handstand, pirouettes, flips, splits, and holds. Bike, run, swim, row, etc, hard and fast. ■ Five or six days per week mix these elements in as many combinations and patterns as creativity will allow. Routine is the enemy. Keep workouts short and intense. ■ Regularly learn and play new sports.

Having Fun will Bring You Back For More!