“Modern medical care should have the same precision and reproducibility in exercise programs that is expected in a dosage of prescribed medicine.”

— Vert Mooney, MD

[Please note: This is a revised version of an earlier essay by Dr. Doug McGuff, MD — JL]


Proper exercise can be likened to a required medicine; one needs it to be of the correct kind and potency, and taken in the correct volume and the optimal dosing frequency in order to be maximally effective.
Proper exercise can be likened to powerful medicine in that it must be of the correct concentration (the intensity of the exercises), its volume (or dose) must be cautiously regulated and it must have an optimal dosing frequency in order to maximize its effects on the body.

Properly performed exercise has the potential to act as a powerful stimulus for positive change within the body, in much the same way that strong medicine does. Consequently, it is the authors’ belief that exercise can be subjected to the same scrutiny, assessment and experimentation that medicine employs in the process of determining an optimum dose amount and frequency that researchers use when inventing a new drug. Such a process should be able to produce a prescription for exercise that would be roughly appropriate for the vast majority of the population.

Let us explore how we could apply this process to exercise. First we must recognize that the human body is an organism, and this organism is able to make adaptive responses to various stimuli and that once identified, such responses should be reproducible across the vast majority of the population of that given organism. A drug is a stimulus that will act upon an organism, and then, under the correct circumstances, the organism produces a response. Likewise, exercise is a stimulus that acts upon the organism, however it is the organism that produces the response under the correct circumstances. When one is researching a drug, the basic equation is as detailed below:


With regard to the stimulus, the basic issues to be identified are the concentration of the drug and the dosage of the drug. Analogous issues in exercise would be the intensity of the exercise and the amount of exercise performed per session. With regard to response, our researchers would wait to record the desired response and note at what point in time this response occurs. The amount of time it takes the response to occur is what dictates an optimum dosing schedule. The key when designing a therapeutic drug is to optimize the concentration so that minimum dosing is required to produce a maximum response. Likewise the key in exercise should be to optimize intensity so that minimum exercise duration and frequency is required to produce a maximum response.

While this may seem complicated, it is actually quite a simple process as long as you control all the known variables and systematically manipulate the unknown variables. Since the desired response is produced by the organism and that response takes time, this is the first variable we should identify because if we are not allowing adequate time for this response while we are testing other variables we will never get a response and will be left wondering what is wrong. So there are several variables we must hold constant.


The first of these variables is Intensity (analogous to concentration). Since our capability with regard to intensity changes on a moment-by-moment basis, the only accurate recording of intensity we can record is either 0 percent or 100 percent — anything else would be guesswork. In addition, reliable data from others in the field note that this intensity (concentration) is required to produce the desired response from the organism. So we must standardize 100 percent intensity; i.e., we should perform the repetitions in the exercise until no further repetitions are possible (i.e., also known as training to failure).

While we have gone into the intensity/stimulus issue in greater detail in our book Body By Science, for our purposes presently it is important that the reader understand that the intensity of the stimulus (i.e., the exercise) needs to be high enough to actually trigger the specific response that we desire (i.e., the synthesizing of more muscle tissue and the up-regulation of metabolism that supports it). Since this is the desired effect we are seeking, it follows that we must provide a specific cause to warrant this specific effect to be produced. As it turns out, the stimulus/intensity required to do this has to be significantly high.


The next variable that must be determined is the proper dosage of exercise. In drug research one generally starts with the lowest dosage expected to produce some response. This is done for a reason, which is to guard against toxicity that could interfere with the organism’s response. And make no mistake; it is very possible to overdose on the exercise stimulus. One of the main causes of exercise “overdose” is confusing the stimulus as being the producer of the response rather than your body as being the producer of the response. 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, and 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 that produces the desired response and an amount of stimulation that 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 “zero” 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 4-6 hours, but if you take it any more frequently than this 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 of the response, but will, in fact, militate against the production of the response and will instead 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.

Our empiric experience training clients, coupled with that of other personal training centers that likewise train clients on a one-on-one basis and record and collocate data from these workouts, the evidence is that the average subject has much less toleration for exercise than was previously thought. If exercise tolerance for the human population were to be charted, it would likely form a “bell graph” distribution. It is the authors’ belief that until fairly recently most people who exercise have been operating way too far to the right on the graph (that is performing WAY too much exercise). This natural mistake has occurred because of selection bias, in that people tend to become interested in exercise (be it running, swimming or bodybuilding) when they show at least some above average potential for it and part of this potential is above-average exercise tolerance. Also people naturally tend to mistake the stimulus (the actual exercise) as the entity that causes the effect (such as muscle growth). As a result, even exercise physiologists and researchers such as the late Arthur Jones have decreased the volume of workouts relative to an already grossly inflated baseline rather than stepping back and examining what the minimum or precise amount of exercise is that might actually be required. This is why for our baseline workout, we recommend that the trainee perform no more than 5 total exercises in a given exercise session. It is important that one not add to, nor otherwise vary this baseline workout or else one’s recordkeeping will be meaningless. Do not fret over the lack of variety. Just because an exercise exists is no reason to perform it, any more than the fact that a drug exists is any reason to take it. If we need a particular medicine to remedy a particular condition, it should be taken in a concentration and dosage that is optimal to produce the desired effect, but not indiscriminately so that is undermines the health of the organism. Variety is not necessary for its own sake and can thwart the production of the effect you are trying to produce. The movements we will outline track muscle and joint function, and if the intensity of your work is adequate they will stimulate all of the muscular structures of your body.

Proceeding, we must standardize the way in which we administer the “dose” of exercise we are prescribing and we also must have an accurate means of recording the response of the organism. The units of a drug dose might be milligrams; the unit of our dose is the repetition. We must standardize our unit so that we maximize the efficiency (intensity) of our dose. Just as we want to eliminate any impurities from our drug, we should eliminate any impurities from our exercise. Such impurities include anything that will allow the muscle to escape from being under continuous load such as heaving, jabbing or throwing the weight. Indeed, we want to eliminate even the smallest amount of momentum so we can know that every second of every repetition represents muscular loading. For measurement purposes our unit must be exactly reproducible. In our “drug” research a milligram is a milligram, is a milligram — all the time, every time. In our research a repetition should be a repetition –all the time, every time. At the authors training facilities we use a time under load protocol, in which the client contracts and extends his muscles slowly (typically taking 10 seconds to lift the weight and 10 seconds to lower the weight). This allows us to insure the purity of the exercise and the precision of our basic unit of recordkeeping.

Additionally, we need to know what to monitor in order to accurately quantify the desired response produced by the organism. Ultimately our desired response is bigger muscles and ideally this is what we would like to measure. Unfortunately, this is a fairly gross change and the units of measure (fractions of inches) are too large to allow us to make the fine adjustments of optimizing volume and frequency. Also, empirical evidence shows that muscle growth can be delayed and variable amongst individuals. What we need is a reliable marker for progress. Fortunately such a marker has been found. We know that a muscle’s strength is directly related to its cross sectional area. In a given individual, if a muscle becomes stronger, it will typically become larger (although this relationship is not always present due to genetic variations previously discussed); or if a muscle is noted to have become larger we will find that is stronger (although how much stronger also has genetic determinants). It has also been noted that a strength gain typically precedes a size gain (this is true even in champion bodybuilders such as the late Mike Mentzer, who noted such a phenomenon in his writings). A subject may gain strength for many consecutive workouts without any change in measurements; but then, in delayed fashion, the size gain will suddenly occur. While size gains may be sporadic and unpredictable, strength gains can always be used as a marker for adequate recovery and super-compensation. Such gains in strength can be reliably found in our workout record provided that the routine is standardized and not varied, and provided our units of performance recording are strictly standardized.


The next issue that must be considered is what is going to be the appropriate dosing interval? And, just as with medicine, it is desirable that the dosing interval be no more than is absolutely necessary (or spaced as far apart as possible) in order to avoid the negative consequences of the stimulus.

One of the biggest misconceptions in exercise is the belief that one must do something “every day.” Evidently it is based on the supposition that de-compensation, or a loss of what you have gained, will occur very rapidly if the stimulus is not applied on a daily or even every-other-day frequency. Recently, one of the authors spent seven 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. He could not find a single source that even addressed this issue much less proved it. Such data as has been amassed, simple logic and empirical data from supervising over 200,000 workouts have caused the authors to conclude that the this supposition is false. 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  –> 7 days –> Response –>  ? days  –>Decompensation

As we refer you to the above diagram we 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; that is, it is up-regulating 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 metabolically expensive (in the extreme), which is precisely 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 metabolic 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 our bodies have made this response it has incurred a huge metabolic investment. The day after the response occurs is simply the soonest time that the organism is capable of dealing with another stimulus — not the best time, just the soonest time. The “ideal” time might actually be several days after the response has been made, when the organism is without doubt fully recovered and overcompensated.

In considering the issue of de-compensation we must also acknowledge that nobody honestly knows when this begins. The authors’ experience suggests that de-compensation does not even begin for a very long period of time (assuming a normal day-to-day existence and not, as in the case of broken limbs, where a limb has been completely immobilized in a cast for several weeks). Indeed, a study that was performed in 1993 in which subjects were made to perform but three sets of negative-only biceps curls, revealed that after 10 days of no activity, the subjects still had not recovered their strength level to the point they had enjoyed prior to the workout stimulus being applied. They concluded that the half time for recovery might extend beyond 12-weeks. Admittedly, negative-only (where someone lifts a weight that is approximately 40 percent heavier than you would normally employ in a typical lifting movement and you then take the weight at the top or fully contracted position and concentrate on lowering the resistance under full muscular control) is a much more advanced and much more demanding protocol. Nevertheless, the actual workout in this instance was but three sets – and the recovery period (not including the period of time required for the adaptive response to be produced; i.e., muscle growth, which would have followed after recovery had occurred) took well over six weeks, 1which would at least suggest that recovery would still be underway during the five to six days after the workout and therefore de-compensation would not even be a factor in such a short time span.

Experienced high-intensity trainers such as Gus Diamantopoulos (from Toronto's "The Strength Room" facility) never train their clients until they are sure that full recovery from the preceding workout has taken place.

The authors know of cases where subjects dropped out of training for periods ranging from 6 to 16 weeks and returned to their workouts with equal or greater strength and size than they had when they last worked out. As you refer to the diagram, please consider why a highly evolved organism would spend at least 7 days making a huge metabolic investment only to allow that investment to deteriorate over an equal (or lesser) amount of time? What evolutionary metabolic/economic sense would this make? This would be like spending a year having a house built that you 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.


Another factor to consider with an exercise prescription is patient compliance. We’ve all known a person who is determined to get back in shape and has made the New Years resolution of getting into the gym four times a week (or some other arbitrary number of days). After about two or three weeks of dedicated effort, he drops out never to return. Apart from not understanding what the stimulus is that he should be employing, nor understanding that the benefits require a considerable recovery period to be produced, this individual sets an unrealistic dosing frequency, overdoses on the stimulus, and then quits working out as a self preservation measure. As with any medication, the dosing interval has been shown to be inversely correlated with patient compliance, meaning that if you set the dose of the medicine such that the dosing interval has to be very frequent (such as three times per day), then patient compliance is going to be infinitely less than if you set the dose such that the dosing interval has to less frequent (such as once a day).

Therefore it only makes sense for exercise to be most efficient if we can find a stimulus-intensity that allows a less frequent dosing interval, as this will ensure that we’re going to have a higher level of compliance, and also a higher level of negative accumulated effects. Apart from the data we presented in Chapter One of Body By Science indicating the severe health risks that attend excessively high levels of physical activity, it should be obvious that training more frequently than is necessary is pointless. People, however, are often filled with angst at the very mention that they ought to take their exercise medicine a little less frequently. Frequent bouts of physical activity, it should be pointed out, do not address any real physiologic needs; rather, it is something that serves to address a person’s psychological needs. Physical training is a very positive experience that often diverts our attention from our daily problems and as such can become a psychologically addictive activity. As a result many trainees become very uncomfortable when less exercise is suggested. But proper training should be a logical process of stimulating a desired physiologic change.

Even when people understand all that we have been discussing, the authors are frequently confronted with the following question: “if what you say is true, why have these other training methods produced so many athletic and bodybuilding champions?” The answer is a statistical term called Selection Bias. People with above-average potential for athletic excellence and bodybuilding are easy to recognize, as they are usually amazingly muscular before they even touch a weight. These people are naturally drawn toward sports and when exposed to any form of training they grow muscle quickly. These people select themselves out as athletes and bodybuilders and pursue these activities for the simple reason that it is easy for them to do well at them. Naturally, they assume their results are due to their superior effort or training techniques when the truth is that they would have excelled if they had taken the garbage down to the curb once a week. The test of a training technique’s efficacy is not how it performs on a genetic anomaly but how well it performs on those of average or below-average genetic potential. High-intensity training will win hands down every time.

As we pointed out in the Introduction to Body By Science, it is a natural mistake to seek advice from those with superior physiques or athletic ability, as their extraordinary physical capacity and physiques are the result of random statistical variation within the species and often 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. For a genetically gifted individual, even if they understand the science behind a high-intensity training approach, many will reject it for reasons they can’t name. Why is this? Primarily owing to the fact that if one is gifted in any endeavor, one will be inclined to make it a vocation (or at least devote a large part of one’s time to it). Consequently, it will come to make up a large part of your identity. In most such endeavors large time requirements are necessary to actualize one’s potential. Paradoxically, in athletics and particularly 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.

This “you can lead a horse to water but you cannot make him drink” situation also exists among the less genetically gifted – but for another reason. They recognize that if a more scientific approach to training improves their results and their 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 longer. 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 fitness enthusiasts, you are probably dissatisfied with your current rate of progress. If so, then take heart from the fact 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 have come to our web site or have purchased Body By Science, then it is quite probable that you will never develop a physique like those pictured in the various health and fitness magazines. Once you have done the considerable soul-searching required 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 once every seven days. If results are not quickly obvious insert an extra rest day until they are forthcoming (at our facilities 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.


— Doug McGuff & John Little





1.) Howell, John N., Chleboun Gary, Conaster Robert. Journal of Physiology, May 1993, 464, pp. 183-196, Muscle Stiffness, Strength Loss, Swelling and Soreness Following Exercise-Induced Injury in Humans (from the Somatic Dysfunction Research Laboratory of the College of Osteopathic Medicine and the Department of Biological Sciences, at Ohio University, Athens).

(Article copyright © 2009, Doug McGuff & John Little. All Rights Reserved)

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