C. Hinsley

29 October 2020


It appears to me that the cause for the public's failure to adopt the High-Intensity Training principles of Arthur Jones, Mike Mentzer, and especially Dorian Yates has been a matter of pedagogy and not of applicability or efficacy. Too often I hear detractors isolating specific features of the training philosophy, bolting them onto their own current training approaches, and using the resultant incompatibility to claim that the entire mode of thought is fallacious. When this is done in discussion channels online, oftentimes HIT's proponents will come along and offer weak refutations that fail to illustrate the opponent's reasoning faults. In efforts to determine what approach is most effective for a given training goal, we must fully consider the assumptions and prescriptions of each system. Though I am presenting HIT as something of an alternative to the "volume (at a sufficient level of intensity) is the primary driver of hypertrophy" maxim so pervasive in contemporary training philosophy, I do not aim to refute that school of thought. My only intention is to clearly lay out what the underlying assumptions of Mentzer's HIT may be and provide a framework from which to make comparisons between it and other training approaches. My exposition here is the result of having read and listened to Mike Mentzer and Dorian Yates in their books, articles, and interviews; it is motivated not only by public misunderstanding but also my belief that Mentzer's material is inaccessible or confusing (or perhaps even esoteric and a little off-the-rocker at times) to many trainees. As always, I recommend going to the origin of the idea in order to form a complete understanding of it; if you want to truly grasp Mentzer's and Yates' training philosophy, you should read their books, watch their videos, and listen to their interviews.


Table of Contents


The normal course for a new hypertrophy trainee

When the typical youth decides to begin working towards increasing his skeletal muscle mass, he consults whatever resources are available to him: parents, a high-school athletics coach, the library, or the Internet. Most often, he is instructed to consume protein one gram per pound of bodyweight, eat more food in general than he is used to, train with weights in the 8-12 repetition-per-set range for 3 to 5 sets, achieve a per-set fatigue level of approximately 1-2 repetitions-in-reserve, allow 45 to 90 seconds of rest between sets, and provide each muscle group 48 hours rest before training again. Immediately he finds that his training efforts are followed by soreness for the next two days, and when he returns to train the muscle group again on the third day, his skill has likely improved in whatever exercises he was performing — especially in the case of multi-joint movements, which can be the most intimidating for the new trainee and thus the most psychologically rewarding to develop skill in. Confidence is increased, the trainee continues to follow this pattern of behavior, and both strength and size gains inevitably come as time passes.

Eventually, the trainee stops progressing. He goes into the gymnasium and finds that one of two scenarios has occurred:

  1. He does not have the ability to train at an increased level of performance and his muscular size gains have slowed to a halt, or
  2. Residual fatigue from his last training session has not fully dissipated, hindering his ability to perform the normal exercise regime.

The popular vernacular for these two scenarios is "under-training" and "over-training" respectively. In order to progress beyond his present stage of muscular development, the trainee must seek productive changes to his training regime.

So the trainee goes back to his coach, his parents, the library, the Internet. He queries for advice overcoming his plateau. Which of the parameters should he change? Should he increase his protein intake? Should he eat more calories? Should he perform more sets, in the case of under-training? How about more repetitions per set? Perhaps less? Should he increase the per-set exhaustion to achieve muscular failure? Should he shorten or lengthen the rest times between sets? What about cyclic prescription alterations, like carb cycling, or undulating periodization techniques? Should he reduce his focus to a lesser quantity of muscle groups at once, emphasizing a select few for a given period of time and refocusing after a month or so? Could it be that the trainee is not performing the exercises efficiently? What's all this about "genetic potential?" Is the trainee nutritionally deficient? How about hormonal deficiencies? Is it time to start using performance-enhancing drugs? The trainee is either paralyzed by being presented with this daunting breadth of possibilities, or he subscribes to a straightforward dogma offered by his counsel.

Nevertheless, there are some pervasive physiological principles that we know ultimately dictate the efficacy of whatever course of action is taken. It is not my intention to provide a comprehensive exposition of the relevant physiological systems in this article, but I will provide some summary notes so as to provide context for further discussion. A quick Internet search will provide plenty of supplementary information if required.

The Central and Peripheral nervous systems

The Central Nervous System (CNS) forms the bulk of neural activity in the body. Skeletal muscular exertion is controlled by the CNS.

The Peripheral Nervous System (PNS) forms a bipartite neurological system comprising the Autonomic Nervous System and the Somatic Nervous System. Any neural tissue that doesn't fall under the heading of the CNS is characterized by the PNS.

Autonomic Nervous System (ANS)