Many coaches and athletes alike sometimes add far too many exercises to their conditioning regime, in an attempt to cover their bases. This, however, merely adds more density to their training. This practice also increases the drain on the CNS for energy required to learn all these particular movements.

“Complexity can increase density and density can increase complexity”

Most coaches only view exercises based upon their metabolic cost to the body, not taking into account the vast amount of sensory information that must be processed by the CNS in order to maintain skill aptitude.

“Less is actually Greater”

Skill development lags behind metabolic development. Some skills require a greater amount of intra and inter – muscular co-ordination before they can be ‘accepted’ into the fascial matrix. It takes sometimes several weeks before a complex lift in the weight room (i.e. squat, clean, snatch etc…) can be adequately processed by the CNS, mean while the metabolic adaptations to these lifts take only a few short days to weeks. Some lifts do not require much learning vs. others, for example a bicep curl vs. an Olympic Clean & Jerk. Aside from the loads used, the complexity of the skill involved can place a stress on the CNS, thus adding to the pool of stressors affecting the CNS at any one time.

“Density refers to the frequency of exposure to a particular training stimuli over a period of time (factoring in the total training time vs rest interval time), but it also could make reference to the number of training stimuli exposed to the athlete at any one time”

It is therefore vital that the coach or athlete develop an exercise hierarchy, by which exercises are classified based upon complexity, speed of execution, and demand placed upon the CNS. Sprinting for example elicits the highest Motor Unit Contraction, close to 100%, whereas a Bench Press only registers in at about 60 to 70%. An Olympic Snatch comes in at a close second to sprinting with a Max Motor Unit involvement of 95%. Therefore to combine these three exercises in the same workout would ‘tap-out’ the CNS considerably more than if you were to combine sprinting with Max Strength Bench Press. After sprinting there should be ‘enough in the tank’ to squeeze in a few sets of bench, unless the athlete hit a Personal Best in the Sprinting, in which case Maximum weights should be eliminated for that day, in order to allow for the CNS to recharge itself.

“Density is related to Intensity”

Complexity, as mentioned above, refers to the sophistication of a particular movement that requires more or less co-ordination. If the CNS is under stress, and has not adequately regenerated, adding complex skill or exercise elements might just tip it into protection mode, thus preventing any further high output energy expenditiure, not to mention learning a new skill. Athlete’s heart rates have been shown to increase by 20 to 30 beats, just by adding more complexity into the training, especially if the complexity is accompanied by increased density and increase load.

“Too much Complexity can increase Intensity”

The athlete must first be allowed to learn complex movements under low load situations and away from other exercises that are simultaneously dipping into the CNS pool. As the skill becomes automated, load can be introduced, and as the athlete begins to show signs of performance adaptations, it is then that perhaps more density can be introduced in the form of other exercises in succession. The coach and athlete must also keep in mind introduction to very high Motor Unit involvement exercises together may not be such a good idea.

“Skill moves from a hind brain to a forebrain to Spinal Loop to Fascial Loop”

It takes roughly 2000 to 3000 repetitions of a movement for each segmental transition. The whole process could take between 5000 to 10,000 movements to finally reach its end stage of motor development. By the time it reaches a ‘Fascial Loop’ stage, it is called ‘Virtuosity’. In this state, creative and imaginative movement is being created internally by the athlete and are not being learned from an external demonstration of sorts. Putting a ‘monkey wrench’ in this whole process is the competition for CNS energy.

“In the inexperienced athlete Sensory Input is less & as a consequence Performance Output follows suit. In the Super Elite athlete the opposite holds true as well as the Output can now influence the Input as well, due to the fact the system is working on ‘Fibre Optics’ vs ‘Copper Wire’ “

As the athlete becomes fatigued, skill execution and adaptation drops off. This is an important note, as many coaches and athletes enter skill training sessions under the state of fatigue, or train a brand new skill element under duress. New Skill must first be introduced under low stress situations, and as it becomes more automated, it can then be done under game like situations. If the same skill that was learned / automated begins to deteriorate, it could be that the athlete’s CNS is fatigued, or other elements of training were introduced increasing the complexity and density, hence shutting down the CNS.