The CrossFit Theoretical Hierarchy of Development

A theoretical hierarchy exists for the development of an athlete. It starts with nutrition and moves to metabolic conditioning, gymnastics, weightlifting, and finally sport. This hierarchy largely reflects foundational dependance, skill, and to some degree, time ordering of development. The logical flow is from molecular foundations, cardiovascular sufficiency, body control, external object control, and ultimately mastery and application. This model has the greatest utility in analyzing an athlete's shortcomings or difficulties.

We don't deliberately order these components but nature will. If you have a deficiency at any level of the pyramid the components above will suffer.

Every regimen, every routine contains within its structure a blueprint for its deficiency. If you only work your weight training at low reps you won't develop the localized muscular endurance that you might have otherwise. If you work high reps exclusively you won't build the same strength or power that you would have at low rep. There are advantages and disadvantages to working out slowly, quickly, high weight, low weight, cardio before, cardio after, etc.

For the fitness that we are pursuing, every parameter within your control needs to be modulated to broaden the stimulus as much as possible. Your body will only respond to an unaccustomed stressor; routine is the enemy of progress and broad adaptation. Don't subscribe to high reps, or low reps, or long rests, or short rests, but strive for variance.