General adapting syndrome
As far back as in 1950, Selye had proposed the concept of defensive ADAPTING of the human body to aggressive STIMULI, both extrinsic and intrinsic, describing all the defensive mechanisms with which the body maintains its structure and functions (with changes only within a limited range) in response to the stimuli (stresses) coming from the surrounding environment (temperature, illnesses, injuries, muscular activities, etc.).
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STRESSING AGENTS
Surgery, infections, traumas (injuries, burns), allergic or immune system reactions, great efforts or emotions, malnutrition, physical agents (heat, cold, sun,) |
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If this stress situation is repeated in time in a somewhat regular way, the body reacts increasing its "defences" and upgrading the potential and specificity of the organic system subjected to stress (SPECIFIC REACTION).
Systemic and non specific reactions
The systemic and non specific reactions occur in accordance with a response that can ALWAYS be divided in three successive phases:
1. - SHOCK PHASE - Acute cortical-suprarenal insufficiency paleness. This is the shock phase in which the body is passively subjected to the action of the altering agent, followed by a counter-shock, in which the body mobilises its defences; in this phase the body's reactions go beyond the actual need for compensation (cold sweat, muscle weakness, tachycardia , low blood pressure, hypovolemia, hemoconcentration, hypoglycemia, hypochloremia, hyperpotassiemia, leukopenia , anuria, gastrointestinal ulcers);
2. - COUNTER-SHOCK PHASE - 3. - RESISTING PHASE - Cortical-suprarenal response. Resisting phase, in which the body increases its resistance against the harmful element; in practice it amounts to all of the systemic and aspecific reactions induced by protracted stimuli, which enable the body to resist the noxious factors attacking it (normalisation of the blood pressure volume, drop in haematocrit, increase in glycemia, increase in the secretion of nitrogen, increase in leucocytes, drop in lymphocytes and eosinophil, decrease in the volume of the thymus and lymphonodes, hypertrophy of the suprarenal cortex and the release of lipid grains);
4. and 5. - BREAKING DOWN PHASE - cortical-suprarenal breakdown. Breaking down phase, in which the body succumbs to the harmful agents; it can occur sooner or later in accordance with the body's response capabilities and according to the intensity of the stress; it can also not occur wen the stress ends soon enough (breakdown, death).
Specific reactions
Hence, according to Selye muscular activity is one of the most important stressors (abnormal stimuli that attack the body), and it is characterised by the fact that it produces a very brief period of shock, followed by very marked counter-shock phenomena.
Stress causes in physical exercise are numerous and of course they mutually compound one another with a cumulative effect. The repetition of the physical stress (physical exercise or STIMULUS), produces a variable effect according to the nature of the intensity of the previous exposition to the physical stress in question, and to the duration of the rest between the two (ADAPTING PHASE). It is in this very phase that the adapting phenomena related to the specific nature of the stimulus emerge and grow more intense.
Systemic and non specific reactions
The systemic and non specific reactions occur in accordance with a response that can ALWAYS be divided in three successive phases:
1. - SHOCK PHASE - Acute cortical-suprarenal insufficiency paleness. This is the shock phase in which the body is passively subjected to the action of the altering agent, followed by a counter-shock, in which the body mobilises its defences; in this phase the body's reactions go beyond the actual need for compensation (cold sweat, muscle weakness, tachycardia , low blood pressure, hypovolemia, hemoconcentration, hypoglycemia, hypochloremia, hyperpotassiemia, leukopenia , anuria, gastrointestinal ulcers);
2. - COUNTER-SHOCK PHASE - 3. - RESISTING PHASE - Cortical-suprarenal response. Resisting phase, in which the body increases its resistance against the harmful element; in practice it amounts to all of the systemic and aspecific reactions induced by protracted stimuli, which enable the body to resist the noxious factors attacking it (normalisation of the blood pressure volume, drop in haematocrit, increase in glycemia, increase in the secretion of nitrogen, increase in leucocytes, drop in lymphocytes and eosinophil, decrease in the volume of the thymus and lymphonodes, hypertrophy of the suprarenal cortex and the release of lipid grains);
4. and 5. - BREAKING DOWN PHASE - cortical-suprarenal breakdown. Breaking down phase, in which the body succumbs to the harmful agents; it can occur sooner or later in accordance with the body's response capabilities and according to the intensity of the stress; it can also not occur wen the stress ends soon enough (breakdown, death).
Specific reactions
Hence, according to Selye muscular activity is one of the most important stressors (abnormal stimuli that attack the body), and it is characterised by the fact that it produces a very brief period of shock, followed by very marked counter-shock phenomena.
Stress causes in physical exercise are numerous and of course they mutually compound one another with a cumulative effect. The repetition of the physical stress (physical exercise or STIMULUS), produces a variable effect according to the nature of the intensity of the previous exposition to the physical stress in question, and to the duration of the rest between the two (ADAPTING PHASE). It is in this very phase that the adapting phenomena related to the specific nature of the stimulus emerge and grow more intense.
