[Neuroendocrine and nutritional aspects of overtraining].
The overtraining syndrome is characterized by an excessive training that results in several adverse effects the main of which being the decay in performance. Its incidence among elite athletes has been experiencing a significant increase lately, which prompted a rush of interest in the search for efficient measures to prevent and treat this condition. It is necessary, however, to clarify possible mechanisms involved in the development of overtraining. Several hypothesis are being proposed, such as a greater activation of both the autonomic nervous system and the hypothalamic-pituitary-adrenal axis, and suppression of the hypothalamic-pituitary-gonadal axis. On the contrary, some studies suggest that the modulation of such systems is but a consequence of the overtraining syndrome and not its cause. Thus, recent hypothesis related to cytokine release, to central fatigue, to depletion of muscle and liver glycogen, and to a reduction in glutamine availability during physical activity are being raised.
Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP.
Marcelo Macedo
MM
Rogero
Renata Rebello
RR
Mendes
Julio
J
Tirapegui
D016207:Cytokines / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005973:Glutamine / Q000378:metabolism; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D018763:Muscle Fatigue / Q000502:physiology*; D009490:Neurosecretory Systems / Q000502:physiology*; D009752:Nutritional Status; D010807:Physical Endurance / Q000502:physiology*; D010913:Pituitary-Adrenal System / Q000378:metabolism; D013177:Sports / Q000502:physiology*
D016207:Cytokines; D005973:Glutamine