One of the most concise definitions of fitness that I’ve come across stated that fitness is merely “the ability to survive to reproductive age and produce viable offspring” (usda.gov). Still more vexing, Meriam-Webster defines finess as “the quality or state of being fit” (merriam-webster.com) Not to oversimplify human nature or introduce too many complex sociopolitical motivations to the discussion, but I propose a few other definitions as these may not aptly describe what is so greatly sought after in our modern civilization.

For some time, fitness has been an intangible, theoretical notion that few people have been curious or brazen enough to accurately define. In 2002, the good folks at Crossfit saw fit to dive into the obscurity while both defining and demonstrating fitness through their unique training platform. The impetus being that “the specter of championing a fitness program without clearly defining what it is that the program delivers combines elements of fraud and farce” (crossfit.com). Crossfit Founder Greg Glassman goes on to delineate the “ten recognized general physical skills. They are cardiovascular/respiratory endurance, stamina, strength, flexibility, power, coordination, agility, balance, and accuracy.” These physical skills compose only one of the three models of fitness. The second “model is the view that fitness is about performing well at any and every task imaginable. The implication here is that fitness requires an ability to perform well at all tasks, even unfamiliar tasks, tasks combined in infinitely varying combinations.” Consequently, Glassman advises “keep[ing] the training stimulus broad and constantly varied. Model three involves energy and fundamentals of biochemistry. This model states that “there are three metabolic pathways that provide the energy for all human action. These ‘metabolic engines’ are known as the phosphagen pathway, the glycolytic pathway, and the oxidative pathway…Total fitness requires competency and training in each of these three pathways or engines.” In conclusion, Glassman points out that “the need for specificity is nearly completely met by regular practice and training within the sport not in the strength and conditioning environment.”

Coach Eddie Lomax, founder and president of the Optimum Fitness Network took the Crossfit concept a step further with his definition that fitness is “the acceptable and deliberate compromise of competence and ability to perform in ALL the areas of cardiorespiratory endurance, strength, flexibility, power, speed, coordination, agility, balance, accuracy and toughness to produce optimum performance results under the greatest amount of circumstances”(ezinearticles.com). Glassman’s and Lomax’s definitions both focus on the ability of the body to exhibit versatility and warns against the limitations of specialization. Glassman presents a much more exhaustive description of the specific elements that will yield the abilities needed to achieve fitness, while Lomax’s assumes one will know how to acquire the individual abilities that contribute to total fitness. I am quite impressed with these definitions because they truly add depth and perspective to such a vague expression and add relevancy to an industry that for far too long ‘eyeball’ measured fitness with mirrors and waistbands, sports competitions notwithstanding.

Now thus far, none of these definitions have incorporated the concepts of health, wellness, or nutrition into fitness although Glassman and Lomax have both written extensive articles on all three. I make this distinction because I cannot describe one of these constructs without using the others to define it. That is to say, one cannot truly achieve fitness while forsaking any of the aforementioned attributes.  Furthermore, I must include the degree of emotional and spiritual repair of a person to fully convey the expanding spectrum of fitness. While most people would agree that fitness is a term that describes physical condition and ability, few would argue that the mind and will of a person play a role in the acquisition of that condition and ability. Similarly, I must insist that the stability and health of the mind is integral to the pursuit and maintenance of fitness. A side note: I think most of us could identify with the person at the gym or in your building that works out “for all the wrong reasons,” is constantly riddled with guilt and exemplifies body image issues beyond what is widely accepted in today’s society…which is another discussion altogether. This person might personify fitness via the two previous definitions but I cannot in good conscience grant said person that concession. Therefore, I offer this humble definition of fitness that is rooted in the world of physics and utilizes the principles discussed throughout this article. Energy is the capacity to perform work via generating force albeit kinetic or potential or any number of forms. Similarly, Fitness is the capacity to make one’s body perform work with precision at various speeds, intensities and durations in all three planes of motion under an infinite number of conditions, sustainable via adequate nutrition and all while internally controlling the body’s neuromuscular systems and emotional responses to imposed stimuli (Dynamorphosis 2009). It’s quite a bit to digest, but ultimately for such an elusive human quality, isn’t it appropriate that it remain difficult to describe? Regardless, time will tell if the ever growing understanding of our species lends credence to this definition or if the scientists of centuries past had it right with the notion that to survive and reproduce is the only fitness that really matters.