The Does-Response Relationship of Exercise, Part II:
The Narrow Therapeutic Window

by M. Doug McGuff, M.D.

In my last article I discussed how your training is a stimulus that acts on your body in much the same way as a medication and how, as with medication, one must precisely modulate the dose and dosing frequency in order to achieve best results. In this installment I will discuss the concept of the narrow therapeutic window, the myth of early decompensation, the problem of selection bias and bodybuilding science, and the need to separate the psychological from the physical when it comes to your training.

The term "narrow therapeutic window" is used in the study of pharmacodynamics (how a drug works in the body). The body is a very efficient homeostatic organism which is very resistant to change and very protective of the status quo. In order to encourage a desired physiological change, a fairly severe stimulus is almost always required...this is true whether the stimulus is a drug or exercise. The problem with most drugs is that there is a narrow window between an amount of stimulation which produces the desired response and an amount of stimulation which produces a toxic response. Generally the more effective a drug is at producing a stimulus, the more narrow the space between a therapeutic and toxic dosage. Another critical observation is that the therapeutic effect always plateaus so that pushing the dose higher ONLY produces toxicity and never produces any additional therapeutic effect. Thus, there is NO benefit to risking toxicity. Once you cross the threshold from a therapeutic level of stimulus into the toxic range the organism does not produce any more of the desired response and most times the desired response is PREVENTED by the toxic effect. For instance, the pain relieving effects of Ibuprofen max out at about 400mg, as dosages go higher there is no more pain relief but you may burn a hole in your stomach lining. With acetaminophen (Tylenol) you can take the required dose every 4-6hrs but if you take it more frequently you will end up on the liver transplant waiting list. The same relationship with dose amount and frequency exists with your training, anything above the threshold dose amount or frequency to produce the desired physiological response will not produce more response....in fact, it will actually prevent the response and produce other toxic effects. Remember, the stimulus-organism-response relationship operates the same whether the stimulus is a drug or your training...the principle remains the same.

As stated in my previous article one of the main causes of exercise "overdose" is confusing the stimulus as the producer of the response rather than your body as being the producer of the response. Once I am able to get someone to understand this relationship, the next problem I encounter is the blind assumption that decompensation of the response will occur relatively quickly. Somewhere, Arthur Jones heard that decompensation occurs in 96 hours, then he repeated it and everyone else repeated it and it became unquestioned gospel. Recently, I spent 7 solid hours in the medical library at the University of Texas Health Science Center at San Antonio performing an extensive literature search trying to find a study supporting this contention. I could not find a single source that even addressed this issue much less prove it. Simple logic and personal experience have brought me to the conclusion that this is simply NOT TRUE.

Please refer to the diagram below for the following discussion and in the diagram consider time as a continuum flowing from left to right......

Stimulus>>Organism>>7days>>Response>>?days>>Decompensation

As we refer you to the above diagram I want you to consider what an expensive metabolic process our desired response is going to be. Remember, we are focused on building muscle, but our body is making GLOBAL METABOLIC ADAPTATIONS. It is upregulating it's metabolic efficiency by synthesizing more enzymes to make all metabolism more capable including aerobic metabolism, anaerobic metabolism, gluconeogenesis, glycogen breakdown and transport, blood buffering agents and of course new muscle growth. All of this new synthesis is EXTREMELY metabolically expensive, that is why your body will not invest in these changes unless a severe stimulus is applied and the organism is left undisturbed afterwards to make these changes. By the time we have produced the response our bodies have made a HUGE investment. Just like you, your body does not make big investments on anything it plans to hold on to for only a short time.

Refer to our diagram above again. By the time we have made our response we have made a huge metabolic investment. The day after the response occurs is simply the EARLIEST time at which the organism is capable of dealing with another stimulus...not the best time, just the earliest time. The best time might be several days later, no one knows because no one has yet explored this time frame. Now with regard to decompensation we must also acknowledge that nobody honestly knows when this begins. My own theory is that it does not begin for a VERY LONG TIME. I know of cases where subjects dropped out of training for 6 weeks and returned with equal or greater strength and size. As you refer to the diagram, I want to ask you a question....why would a highly evolved organism spend 7 days making a huge metabolic investment only to allow that investment to deteriorate over an equal (or lesser) amount of time? What metabolic/economic sense would this make? This would be like your spending a year having a house built that you would expect to crumble to the ground within a year of it's completion date. If the human organism were this metabolically inefficient we never would have survived as a species.

Once one can understand the concept that an adaptive response takes time and that early decompensation makes no metabolic sense; one will see that "periodization" of training makes no sense whatsoever. Realize that "active rest" is an oxymoron. What your body needs between intense workouts is not a "submaximal workout", or "active rest"; what it needs is rest...period. The concept of periodization does not address any real physiologic needs; rather, it is designed to address a person's psychological needs. Training activity is a very positive experience that diverts our attention from our daily problems and as such can become a psychologically addictive activity. As a result many subjects become very uncomfortable when I try to get them to train infrequently they almost invariably slip in extra exercise. But proper training should be a logical process of stimulating a desired physiologic change.

An example from my medical practice will highlight my point. If I have a patient with a medical problem that is purely physical in nature I will prescribe the simplest most direct treatment available. If you have strep throat, I will give a single penicillin injection. If you have high blood pressure, a once daily pill is in order. If, on the other hand, you are suffering from something that has a large psychosomatic component to it, then I will make the treatment plan complex. I will prescribe one pill to be taken every eight hours on an empty stomach, another to be taken every six hours with food. I will give you specific dietary and sleep guidelines. All this activity and focus acts to divert your attention from the psychological problems that are contributing to your symptoms and miraculously you get better. Realize that periodization is designed to satisfy a neurotic addiction to exercise rather than the requirements of productive exercise. It is a method of trying to deal within the constraints of overtraining rather than eliminate overtraining to begin with. What you desire to produce are physical results, thus you should maximize the physical aspects of training and get your psychological needs fulfilled elsewhere.

Even when I get my clients to understand all that I have been discussing, I am frequently confronted with the following question: "if what you say is true, why have these other training methods produced so many bodybuilding champions?" The answer is a statistical term called SELECTION BIAS. People with above-average potential for bodybuilding are easy to recognize...they are usually amazingly muscular before the even touch a weight. These people are naturally drawn toward strength sports and when exposed to any form of training they grow muscle quickly. These people select themselves out as bodybuilders and pursue this activity because it is easy for them to do well at it. Naturally, they assume their results are due to their superior effort or training technique when the truth is that they would have grown if you had thrown tomatoes at them. The test of a training technique's efficacy is not how it performs on a genetic freak but how well it performs on those of average or below-average potential. High intensity training will win hands down every time. In short, it is a natural mistake to seek advice from those with superior physiques, even though their physiques may have been produced in spite of, rather than because of their training techniques. Remember, 99% of people die in bed; but that doesn't mean we should assume beds are killing people.

Having explained with the utmost clarity and logic the reasons for the superiority of the high intensity approach to training, I know the vast majority of those who read this column will not apply my advice. Why? I am not sure, but I have a theory that may encourage a few more people to give this a try...so here goes. Throughout my career in emergency medicine I have been amazed at the human capacity for self-delusion; we are the only animal in nature that can lie to itself. We do it so well that the majority of people are totally unaware of what motivates their actions, most people do not act to achieve consciously named goals; rather, they act to placate subconscious psychological value conflicts. If this sounds cynical, so be it...I am convinced it is true...even in myself. Such self-delusion might explain why high intensity training might be rejected by those with great genetic potential as well as those with average-to-below average potential.

For a genetically gifted individual, even if they understand the logic of H.I.T. most will reject it for reasons they can't name. Why? If you are gifted in any endeavor, you will tend to make it a vocation or at least devote a large part of your time to it. As such this will make up a large part of your identity. In most such endeavors large time requirements are necessary to actualize one's potential. Paradoxically, in bodybuilding it actually is a requirement for a small amount of time to be spent training in order to produce results. For someone who feels he has the potential to justify devoting his life to bodybuilding, learning that best results will be produced with little time commitment can be psychologically devastating. Such a person is now left with a huge void to fill. Rather than using this time for more meaningful and challenging endeavors, most such people will turn their backs on the facts. Instead, they will look to their own superior physiques and use their perceived results to justify hours spent in the gym, fortunes spent on supplements, and entire weekends spent preparing and freezing meals for the next week.

As to those who are less genetically gifted, most behave with equal irrationality. Even if they understand the salient concepts, most will reject them without giving them a trial. Why? They recognize that if this does improve their results and rate of progress it may also end up pointing out the limits of their potential. Many prefer hype and empty promises to facts because it allows them to hold on to their fantasies. Many commercial interests in the bodybuilding field deeply understand this phenomenon and are getting rich off of it. There are multitudes of "horse and buggy" bodybuilders who are rejecting the automobile and airplane because they know it won't carry them to the moon.

If you are like most bodybuilding enthusiasts, you are probably dissatisfied with your current rate of progress. If so, what is this doctor's prescription for you? First, realize that you are probably nowhere near your final muscular potential; but also realize that if you had truly great potential you would already be massive beyond belief, no matter how you trained. If you are reading this article it is most likely you will never have a physique like those pictured in the muscle magazines. Once you have done the considerable soul-searching to put your goals in proper perspective, then you are ready for action. First, take a break from training for 10-14 days. Next resume training using only 3-5 exercises and train every 4th-5th day...if results are not quickly obvious insert an extra rest day until they are forthcoming (at Ultimate Exercise we find every 7th day to be average). Lastly, have the courage to refrain from training until you are recovered....the only thing you will regret is the time you wasted by training more frequently.

For those readers who live within a few hours of upstate South Carolina please consider making a drive to visit Ultimate Exercise, my one-on-one High Intensity Training Center in Seneca. We can put you through a 15 minute routine that will change the way you think about bodybuilding forever. Who knows, it may even be worth driving in once every 7-10 days to perform High Intensity training under professional supervision in the "ideal exercise environment". To schedule an appointment call (864)886-0200.