The two most important principles of physical training
For most of us, the basic mechanisms behind training and conditioning would seem straightforward: if we train hard and consistently, we will gradually become fitter, faster, or stronger. And that is true. However, as we might expect, it is very much an incomplete picture of the truth, and it is what is missing from this picture that often determines our success or failure.
As early as 1936, Hungarian-Canadian endocrinologist Hans Selye (1907–1982) wrote in the scientific journal Nature about his emerging research on physiological responses to various biological stressors, amongst which he included physical exercise. He described a “generalized effort of [the body] to adapt itself to new conditions,” and introduced the term general adaptation syndrome. In 1941, a student of Ivan Pavlov, Russian physiologist Georgy Vladimirovich Folbort (1885–1960), explained the general mechanisms of exercise, fatigue, and recovery. Then in 1950, Selye published in the British Medical Journal his first academic paper describing his theory on physiological stress. (In so doing, he coined the term as we use it today in this context.) Recognising the importance of this theory to the field of sport science, Russian biochemist Nikolai Yakovlev (1911–1992) subsequently began to investigate the numerous biochemical changes associated with exercise and recovery, publishing his first paper on the topic in 1955. His discoveries form the foundation of two of the most important principles in modern sport science theory: specificity and super-compensation.
Specificity
In the most simple terms, the Principle of Specificity tells us that adaptation is determined by the nature of our training. This principle applies equally on every scale — cell, organ, and organism.
On a microscopic scale, the types of stimuli that we receive from our training influence all aspects of our cellular metabolism, including nutrient transport, bioenergetics (production, storage, and consumption of energy), remodelling, genesis (creation), and apoptosis (destruction). Bones thicken and harden in response to mechanical bending; connective tissues (such as fasciae, tendons, and ligaments) broaden and elongate to accommodate our functional range of motion; muscles hypertrophy (enlarge) as a consequence of damage under tension, and increase their density of mitochondria in response to demands on aerobic respiration.
Similarly, on a macroscopic scale, training stimuli determine the development of our functional capabilities. Heavy lifting increases the amount of force that we can sustain and generate; sprinting develops our power and rate of force production; extended exercise improves our endurance, energy storage, and efficiency of movement.
The purpose of this adaptation, of course, is that the body improve its ability to meet the demands imposed on it.
This principle may appear self-evident, but its implications are so often overlooked.
Some years ago, a member of my gymnasium sought my advice about improving his marathon times. Lightweight and sinewy, Brian had an ideal physique for distance running, and he boasted a long, continuous history of strength and endurance training and conditioning. He carried no injuries, and he had no trouble completing the distance of 42.2 kilometres (26 miles) comfortably. Quite simply, he was in superb condition. At the age of sixty-seven, he was probably never going to challenge Eliud Kipchoge to be the first to break the two-hour barrier. However, he took the sport very seriously, and was frustrated by the stagnation of his times. In recent months, he had doubled his training volume, and he was feeling good and recovering well. Ostensibly, he had every reason to expect improvements in his performance, but he was not getting any faster.
Listening to his story, my immediate thought was, “why would you?”
Brian was making a classic training error: in an effort to run more quickly, he was running farther. But his speed was not limited by his efficiency or endurance; it was limited by his power and mobility — stride rate multiplied by stride length. He lacked what we sometimes describe as speed skills. What he required, therefore, was speed training.
After Eliud Kipchoge broke the two-hour barrier and his own marathon world record, commentators around the globe voiced their amazement at how he could have achieved such a feat of endurance, especially having come from a track background. But his track background was precisely what qualified him to do it. Runners of his calibre do not have difficulty completing such distances; their challenge is reaching and maintaining a speed that is competitive amongst their peers — or, as it was in this case, adequate for breaking a record. Long-distance runners, both amateur and professional, would do well to learn from his example.
Every pursuit or discipline requires a unique set of physical capabilities. An understanding of training specificity tells us what or which activities will develop those capabilities. All we need to know thence is how and when.
Super-compensation
The term super-compensation originally described the augmentation of muscle and liver glycogen and muscle phosphocreatine, in response to training and during post-exercise recovery. Now, it more broadly describes any or all of the physiological mechanisms associated with exercise and recovery, including, but not limited to the adaptation of skeletal, smooth, and cardiac muscle tissue, osseous (bone) tissue, and nerve tissue. Modern usage of the term, therefore, incorporates earlier theories, such as those described by surgeons Henry Gassett Davis (1807–1896) and Julius Wolff (1836–1902). Tudor O. Bompa defines it in his book Periodization: Theory and Methodology of Training (Sixth edition) as “a relationship between work and regeneration that leads to superior physical adaptation as well as metabolic and neuropsychological arousal before a competition.” Curiously, this definition equates the term to the relationship between processes, rather than to the processes themselves. Nevertheless, the distinction is a matter of semantics.
There exists some debate over the nomenclature, but which is unnecessary to our understanding. To propose a simpler definition, super-compensation is a temporary state of improvement, physiological and functional, that occurs in response to training. For brevity, I will hereby explain the process only in terms of our physical capacity, but it should be understood to apply equally to the physiology and biochemistry enabling that capacity.
Let us examine, visually, what we sometimes refer to as the super-compensation cycle. The figures below (Figures 1.1–1.5) illustrate its five distinct phases, with our physical capacity varying as a function of time. The magenta line begins at the origin, representing a state of homeostasis, which is simply our original condition, prior to the application of a new training stimulus. Thus, the height or depth of the line thereafter indicates our capacity at any given time, relative to that state.
Following the application of a training stimulus, our body undergoes numerous physiological and biochemical changes, which manifest themselves as fatigue (Figure 1.1). Our physical capacity is consequently reduced, falling sharply below the level of homeostasis.
After a period of time, with rest, our capacity reaches a local minimum, as the body sets about compensating for disruptions to its homeostasis. The process of recovery (Figure 1.2) then begins, with the removal of waste products, correction of chemical imbalances, replenishment of fuels, and repair of microscopic damage caused by the stimulus.
It is critical during this period that we avoid any further stimuli that would tax the system in a similar manner, lest we reduce our capacity further below homeostasis, and regress in our training.
Once homeostasis is restored, with further rest, our physical capacity continues to advance, entering the state we know as super-compensation (Figure 1.3). This condition incorporates such changes as increased fuel storage, elevated levels of hormones and other metabolic chemicals, and the growth and remodelling of tissues. The longevity or transience of these changes is specific to the type of change, and largely independent of the others’.
Having reached a local maximum, and with yet further, superfluous rest, our physical capacity then begins gradually to return to homeostasis (Figure 1.4), in a process known as involution.
Both the third and fourth phases of this cycle represent a state of super-compensation, during which time we are fitter, faster, or stronger than we were before the introduction of the training stimulus. In order to exploit this augmented state, therefore, we must introduce a new and, ideally, more challenging training stimulus at some point during this period.
Eventually, after a prolonged period of inactivity, our physical capacity declines beyond homeostasis into a state of detraining (Figure 1.5).
It is worth noting, however, that the duration of the super-compensated state is not insignificant. With the exception of those athletes who are approaching the limits of their physical potential, our window of opportunity to capitalise on earlier training is quite broad. And structural changes, particularly, tend to be persistent. It has been found, for example, that short-term training frequency has no significant impact on hypertrophy.
Another member of my gymnasium, Peter, was an archetypal bodybuilding enthusiast. He followed a high-volume training regimen, which was organised into some permutation of the classical six-day split. And he possessed a sculpted physique, the culmination of years of dedication and consistency. Given his diet, physical geometry, and genetics, he should have been impressively strong. However, he struggled almost perpetually with some form of tendinopathy, most commonly of the elbow or anterior shoulder.
The reason was obvious: over-training. And he, himself, conceded that point. Nevertheless, he was loath to rest for fear of losing his hard-won size and strength.
Peter had a phobia common amongst all athletes, whereby it is imagined that our condition declines almost as quickly as it is develops. This is simply not true. In fact, one of the greatest predictors of training success is the discipline not to train, but to allow the requisite time for recovery and super-compensation. And amongst amateur and professional athletes alike, chronic injury is one of the primary reasons for retirement from sport.
It should be understood that the super-compensation cycle is, above all, a conceptual model of our physiological response to the application of a training stimulus. In the simplest terms, it describes how we exercise, fatigue, recover, strengthen, and languish. And it highlights one of the most important and overlooked truths of training: that we do not improve with exercise, but rather with recovery. Exercise is only the catalyst to our development.
The progression of the super-compensation cycle, or part thereof, depends upon our choice of exercise, and our management of exercise intensity, volume, and frequency. Finding the perfect balance between these training variables is a complex task, and the primary criterion that separates amateurs from professionals. However, a basic understanding of the factors affecting the cycle can help us all make better decisions about our training.
Whether our performance has plateaued, or we have regressed, or we have experienced ongoing soreness or injury, it is highly likely that we have overlooked some aspect of the Principle of Super-compensation. Many of us, including, astonishingly, some athletes and coaches at the highest levels of sport, are scarcely cognisant of its implications. More commonly, though, it is just forgotten in a culture of earnestness and determination. Focused on the destination, we lose sight of the path.
How, then, can we apply an understanding of this principle to our training?
First, our training should be organised such that successive bouts of exercise are performed at the peak of super-compensation (Figure 2.1). At the height of our capacity, we can apply and tolerate more challenging stimuli, and hence maximise the rate of our development.
Of course, outside of a laboratory, it is impossible to determine exactly when our peak is. With trial, error, and observation, however, we can easily arrive at a good estimate. And if we have any doubt, it is prudent to overestimate the amount of rest we require, rather than to underestimate it. A good heuristic to follow, especially when programming our more demanding training sessions, is to allow for one full day of rest after we can discern no more soreness, stiffness, or fatigue.
When successive bouts of exercise are untimely (Figure 2.2), we limit our potential for advancement. Similarly, if they are excessively early or frequent (Figure 2.3), such over-training can actually damage our performance and promote injury. The importance of adequate rest cannot be overstated.
After training frequency, training volume has the greatest impact on the progression of the super-compensation cycle. Volume, which in this context can be defined as the total amount of physical work performed during a bout of exercise, profoundly influences the extent of our subsequent fatigue, and hence the time required for recovery and super-compensation.
A low training volume (Figure 3.1) generally provides a stimulus similar to that of a higher volume, but whilst requiring a significantly shorter recovery time, and hence leading to earlier super-compensation. (This phenomenon is easily explained by the Principle of Specificity.)
Except in such cases that tolerance to exercise volume is our goal, minimal training volume per bout of exercise results in a maximal net training effect (Figure 3.2). Lower volume leads to earlier recovery, which permits more frequent training. Thus, less in the short term equates to more in the long term. Our performance capabilities, by contrast, are shaped by exercise intensity.
The Principles of Specificity and Super-compensation govern all of our training and conditioning. Whilst their application is difficult to master, their basic premises are intuitive and easy to grasp. Through trial, error, consideration, and adherence to these principles, we can avoid the common pitfalls, and find success in reaching our training goals.