Neurological vs. Anatomical Stressors
Training effects the body two ways, through the nervous system and through direct effects on the musculature and associated tissues.
High volumes of work tend to place more stress on the musculature, while high intensities of work stress the nervous system. In fact, it is this stress on the nervous system that represents the foundation of strength-oriented training.
This is why a larger volume of work will create a longer-lasting increase in strength than high intensity work. The changes occur in the tissues of the body, rather than being short-term neurological adaptations.
Neurological training is accomplished by either using maximal loads, submaximal loads moved with maximal acceleration, or to a lesser extent, using submaximal loads repeated until muscular failure. These are the maximal effort method, the dynamic effort method, and the repeated effort method, respectively. In all instances, reps are kept from 1-6 and typically longer rest periods from 3-5 minutes are called for.
Anatomical training on the other hand is accomplished with the repeated effort method and a higher volume of work. The repeated effort method only becomes neurologically taxing when sets are taken to the point where it requires a concentrated effort to complete. In comparison to neurological training, anatomical training uses reps in the 5-12 range along with shorter rest intervals, from 1-2 minutes.
Bear in mind that anatomical changes are primarily a function of volume, and that the rep range prescribed is largely due to this. Reps between 5 and 12 allow for the volume to be maximized with a heavy enough weight to cause adaptation. A high enough volume of neurological work can and will do the same thing, but the systemic effects of training in this way would make it unadvisable in most instances.