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The General Adaptation Syndrome (Part I)
The theory of GAS was formulated in the middle of this century by Dr. Hans Selye is some time called his "stress theory" but more commonly the General Adaptation Syndrome. "GAS" provide a framework from which most exercise programs and training cycles can be designed. Dr. Selye s clinical observation with humans and experiments with mice and rates led him to propose a three stages process employed any living organism when adapting to a stimulus. The disrupting stimulus is called a stressor and may be beneficial (exercise) or harmful (germs). GAS proposes that when any stressor such as physical trauma, infection, heat, fight is imposed on a living organism, the organism's initial response results in decrease in its ability to cope with additional stressors. This is called the shock or initial alarm stage of GAS. If you are exposed to a flu virus, for example, your ability to cope with exercise is greatly reduced. As time passes after the exposure, however, your body should make internal adjustments that result in adaptations so that future exposure to original stressor in particular, and to other stressors in general, will be less disrupting to homeostasis.
Reversal of the shock phase is termed counter shock, and it leads to the resistance phase of GAS. The effect of adaptation to a given stressor on your body's ability to cope with other stressor is called cross resistance. This is the way for example; a person who stays in shape through regular exercise can better withstand the pressures of work or the common cold.
If multiple stressors are imposed on your body, counter shock may not occur, or the resistance phase may deteriorate your body, counter shock may not occur, or the resistance phase may deteriorate into the third or exhaustion phase of GAS. The possible negative effects of multiple stressors are referred to as cross sensitization. Failure to recover from the shock phase, or the exhaustion phase of GAS, may also occur from a single very potent stressor, or exposure to a given stressor for a prolonged period of time. Severe physical trauma from a car crash, for example may result in death. In a less extreme illustration heavy physical exercise day after for many weeks will probably result in over training, which is a manifestation of exhaustion phase of GAS.
The phasic structure of Dr. Selye's adaptation theory is the basis for the concept of variation and training cycles for both general exercises and specialized conditioning for athletes at all competitive levels.
An additional and very important concept of GAS is that of the body's specific and non specific responses to stressors. The adaptations muscle fibers is of course, specific to exercise demands made of fibers (exercise specificity principal). The new concept here is that no matter what type of exercise demand, or what stressor in general, is imposed affect your body, a non specific response will also occur. Non specific responses affect your body as a whole trough the nervous system and hormonal and other biochemical processes.
The ultimately concept for you to grasp is that all stressors of whatever types result is same essentially the same non specific effects in addition to their own specific effects. A strenuous workout program results in specific bodily adaptation and the same non specific responses that were caused by the pressure of the work, or the term paper due to next week. Since non specific stressor responses are additives, the exhaustion phase of GAS may result as cumulative effect of may seemingly minor stressors.
Thus in planning your exercise program, it is prudent to consider the other stressors in your daily life, as well as during special periods of abnormal pressure and commitments. World class athletes in a number of countries are monitored regularly for signs of excess stress, which is technically defined as the total result of bodily responses to stressors. Typically their blood and urine parameters are monitored, as well as their resting heart rate and blood pressure. You however can suspect excess stress if you experience a loss of appetite and weight, sleep disorder, gastrointestinal ulcer, a lack of, or decrement in training progress, or just a general feeling of constant fatigue and ill health. The fastest and only real cure for this problem, if indeed it is manifestation of exhaustion phase of adaptation, is to decrease the level of stressors acting on your body. May be you need to take a vacation, or to reduce the intensity and duration of your exercise program, or to cut back on other activities what ever you can manage at the time.
Application of GAS
An application of the above theory to exercise program planning indicates that
a) Exercise program should start gradually to ease trough shock or initial alarm phase of GAS and then slowly over the period of weeks, intensify to the desired level (an initial decrease in your strength or physical feelings may occur, this is the alarm stage of GAS).
b) The content, intensity and duration of workouts should not remain constant, since the body could rapidly adapt to a constant stressor level and improvement would stop.
c) Occasional breaks or layoffs from your regular exercise program are needed to reduce and change stressor input to your body and thus to avoid the exhaustion phase of GAS.
Typical periods to apply these three concepts are one or two weeks for initial phase of training (or so called re adaptation after a layoff) six to ten weeks for the major portion of a training cycle, and one or two weeks for a break, or better still a change to some other physical activities resulting in what's referred to as "active rest."
GAS is cyclic and fluctuating in nature, and by training in a similar manner you can expect to make greater gain over longer periods.
The basic idea of GAS can also be applied to responses of your body that occur over other periods. You can consider, for example a single one or two hours workout as composed of shock phase at the start when you feel tight and uncomfortable, followed by a resistance phase once you are warmed up and accustomed to the activity level, and finally an exhaustion phase when fatigue sets in. Dr. Selye himself has made an analogy of GAS to the human lifespan by analyzing characteristics of childhood, adulthood and old age. For the purpose of conditioning our bodies, training cycles of few months, duration will be the main focus of example applying GAS to exercise.
By:Khizer Hayat RajaSr. Lecturer in Physical Education & SportsInternational Weightlifting Coach & ExpertE mail: wlexpert@yahoo.comhttp://www.articlesbase.com/extreme-sports-articles/the-general-adaptation-syndrome-part-i-2773104.html
