Pathophysiology of Overtraining Syndrome
The exact reasons for the various physiological changes are not fully understood. However, it is generally agreed that the physiological adaptation to stress involves a complex neuroendocrine response. Research suggests:
Underperformance
· Inadequate recovery of muscle glycogen resulting in sore muscles and reduced performance.
· Reduced glycogen also has the affect, through reduced energy, of decreased rowing performance.
· Inadequate recovery of muscle glycogen resulting in sore muscles and reduced performance.
· Reduced glycogen also has the affect, through reduced energy, of decreased rowing performance.
Hormonal changes
· The balance between the nervous system and the hormonal system is disturbed. This results in a decreased ability for the body to repair itself during rest periods.
· Increase in stress hormones, such as cortisol and adrenaline in underperforming athletes, may cause mood changes.
· A low teststerone:cortisol ratio may follow in response to overreaching cause a change in the balance of anabolism to catabolism.
· There is a reduced response to insulin-induced hypoglycaemia, suggesting hypothalamic dysfunction.
· Noradrenaline levels are higher.
· The balance between the nervous system and the hormonal system is disturbed. This results in a decreased ability for the body to repair itself during rest periods.
· Increase in stress hormones, such as cortisol and adrenaline in underperforming athletes, may cause mood changes.
· A low teststerone:cortisol ratio may follow in response to overreaching cause a change in the balance of anabolism to catabolism.
· There is a reduced response to insulin-induced hypoglycaemia, suggesting hypothalamic dysfunction.
· Noradrenaline levels are higher.
Amino acids and central fatigue
· Many of the symptoms appear to be related to the brain.
· There is an excessive strain to the nervous system during training
· There are increased levels of the amino acid tryptophan (related to lethargy) into the brain. This is converted to serotonin, which causes central fatigue originating in the brain.
· Central fatigue in the brain causes a decreased activation of fast twitch muscle fibres.
· The neurotransmitter 5-hydroxytryptamine (5HT), which is widespread in the central nervous system, has been linked to determining tiredness and sleep. Changes in 5HT levels may account for symptoms of overtraining affecting sleep, causing central fatigue and loss of appetite.
· Many of the symptoms appear to be related to the brain.
· There is an excessive strain to the nervous system during training
· There are increased levels of the amino acid tryptophan (related to lethargy) into the brain. This is converted to serotonin, which causes central fatigue originating in the brain.
· Central fatigue in the brain causes a decreased activation of fast twitch muscle fibres.
· The neurotransmitter 5-hydroxytryptamine (5HT), which is widespread in the central nervous system, has been linked to determining tiredness and sleep. Changes in 5HT levels may account for symptoms of overtraining affecting sleep, causing central fatigue and loss of appetite.
Immunosuppression
· Raised cortisol levels (the body’s stress hormone), reduced salivary immunoglobulin and low glutamine levels appear to contribute to immunosuppression.
· Raised cortisol levels (the body’s stress hormone), reduced salivary immunoglobulin and low glutamine levels appear to contribute to immunosuppression.