In 1932, physiologist W.A. Engelhardt, for the first time introduced the definition of the training process as a physiological breakdown that serves as a specific stimulus for the subsequent adaptive recovery process. While Engelhardt’s experiments worked with laboratory animals, injected drugs, and introduced stimuli far above what the animals were accustomed to, this idea became the starting point for the concepts of quantitative human training and levels of recovery in athletes. In 1936, Austrian (later Canadian) endocrinologist Hans Selye expanded on Engelhardt’s hypothesis and wrote about a stress condition known as general adaptation syndrome (GAS).
Selye first observed the symptoms of GAS after injecting ovarian extracts into laboratory rats, an experiment he performed with the intent of discovering a new hormone. Instead, however, he found that the extract stimulated the outer tissue of the adrenal glands of the rats, caused deterioration of the thymus gland, and produced ulcers and finally death. He eventually determined that these effects could be produced by administering virtually any toxic substance, by physical injury, or by environmental stress.
He was able to extend his theory to humans, demonstrating that a stress-induced breakdown of the hormonal system could lead to conditions, such as heart disease and high blood pressure, which he called “diseases of adaptation.” Selye observed that patients suffering from different diseases often exhibited identical signs and symptoms. They just “looked sick” he explained in his theory.
This clinical observation may have been the first step in the recognition of “stress” in physiology and medicine. Later, finding an acceptable definition of stress was a problem that haunted Selye his entire professional life. In a landmark paper published in 1950, Selye’s writings concluded, “Stress, in addition to being itself, was also the cause of itself, and the result of itself.”
The three stages of GAS, as proposed by Selye include, an initial alarm phase, as the body fails to keep up with the sudden increased metabolic demands caused by select stimuli—the introduction of a drug, increase in physical effort, or extraordinary environmental issue, etc. The end of this stage is characterized by likely events such as lowered resistance which is perhaps caused by depletion of lymphatic tissue for example.
Following this is a resistance phase, whose duration varies, depending on the strength of the stimulus, during which the animals maintain a heightened state of resistance and tolerance to the noxious agents, environmental issue, or physical assault.
Eventually, however, unless recovery occurs as a result of the elevated metabolism being sufficient to combat the added stress on the tissue, a slate of progressive exhaustion will develop, with illness, injury, or even death resulting shortly thereafter depending on the nature of the stimulus.
This is the exhaustion phase. The staleness seen with prolonged overtraining in cross country runners may be analogous to Selye’s stage of exhaustion.
Periodization has been defined as an exercise system, that if designed correctly, would help to prevent overtraining while optimizing peak performance through progressive training cycles. Thus, periodization is a way of both applying GAS, and managing stress, so that end-stage exhaustion is not the chronic result. It is a strategy by which variables, such as volume, load, and training frequency (density) are all varied with the intention of the realization of this goal. The foundation of periodization is the application of just enough stress to keep the athlete in the resistance stage without ever getting into the exhaustion stage.
* Training Resource: Peaking Workouts for Cross Country Runners
The Russian, Leonoid Matveyev is regarded as the father of modern periodization. He analyzed the results of the Soviet athletes of the 1952 and 1956 summer Olympics and compared successful and not so successful athletes and their training schedules.
In the early 1960’s Matveyez outlined his principles of training based on the application of the scientific work of Selye, and years of his own coaching and studying athletes. Although his work has often been cited for improving the quality of coaching and training over the last 60 years, his original text does not include citations nor references for the claims being made in it. Although anecdotes can be useful for informing research in the field of athletic training, they are insufficient to make strong claims about the importance of periodization.
Historically, the concept of periodization was created by Matveyev, but it was popularized in the Western World by the Romain, Tudor Bompa, to help manage the stress of sport with an emphasis on the area of resistance training. Matveyev did not apply the rigor of the scientific method to his studies and review. He did not use a control group or clinical trials to describe his results.
Since then, however, it has been the belief among coaches that periodized resistance training results in greater increases in muscle size and strength compared with non-periodized approaches. Although some scientifically controlled studies suggest that periodization leads to greater increases in muscle size, others have shown that the increases are similar after periodized or non-periodized resistance training programs.
So, does this mean periodization as described by Matveyev and Bompa is just a training fallacy? No, not all. While the muscular size and strength gains shown between periodized and non-periodized training appear to be the same, consistent studies have shown there to be quite a difference in metabolic improvement between the two opposite training approaches, with the periodized model being far superior to the non-periodized model.
* Coaching Resource: Advanced Topics Symposium in Cross Country
Cross country running training is all about improvements to both the specific muscular sub-system involved in the direct action of distance running movement and the improvement to metabolic function regarding managing carbohydrate and fat molecules as fuels for often repeated muscular contractions. Why should cross country running coaches rigorously follow periodization? The answer lies in metabolic improvement where every study suggests that the ability to increasingly better manage fuels follows the GAS principles very closely.
It is important, however, to never let a distance runner get into the exhaustion phase. Metabolically, entering that stage is the root of chronic performance plateaus and overtraining issues. Periodization is the strategy for managing that this does not happen.