In this lecture from early 2009, Coach Greg Glassman unifies fitness and health. This talk presented a revolutionary new component (a three-dimensional model) that had the potential to both redefine and unite the health and fitness fields forever.

Health can now be concisely and precisely defined as work capacity across broad time, modal, and age domains. Work capacity is the ability to perform real physical work as measured by force x distance / time (average power). Fitness is this ability in as many domains as possible.

Science is about measurement and prediction. Without measurable, observable, repeatable data concerning the fundamental physical units of kinematics (mass, distance, and time or MKS) there is no science of human performance. This is true of the planets, automobiles, and exercise.

Physical output can be measured in terms of foot-pounds/min. We move our own bodies and we move external objects. We can measure how heavy those bodies and objects are, how far they travel, and in what time period. Your ability to move large loads, long distances, quickly, in the broadest variety of domains is fitness. And the ability to sustain that fitness throughout your life is a defining measure of health.

Glassman’s prescription for achieving this fitness is constantly varied high intensity functional movements. We can accurately predict improvements in work capacity across broad time, modal, and age domains through this prescription. There are tens of thousands of examples at this point.

The new component introduced in this lecture is age. Fitness can be graphed in two-dimensions with duration of effort on the x-axis and power on the y-axis. At each duration, we average your power capacity across a variety of modal domains (skills and drills). This creates a power curve, the area under which is your work capacity across broad time and modal domains (aka fitness).

We can now add a third dimension to this graph, the z-axis, which is age. By reassessing your two-dimensional fitness at various times throughout your life, we graph the form of a solid. The power curve takes on the shape of a plateau or blanket. This three-dimensional graph is a defining measure of health. Health, therefore, is nothing other than sustained fitness.

In the first half of this lecture Coach covers the first three operational models of fitness originally published in his seminal What is Fitness article, and how they become united by the work capacity graph.

In the second half he explains the fourth model, the sickness, wellness, fitness continuum, and how that becomes subordinate to the metric of maximizing the volume of work capacity across broad time and modal domains throughout your life.