Neuro-endocrine fatique

Nervous system is shared into afferent and efferent. Efferent is shared into autonomous and somatic. Somatic nervous system innervates skeletal muscles and always leads to muscle stimulating. Autonomous nervous system innervates smooth and cardiac muscle glandulas and gastrointestinal neurons, which leads to stimulus or inhibition of effector stations.

Athletes can survive two types of overtrainness. First typ, Basedow’s overtrainness, is related to sympatic, or parasympatic dominance. It results from sympatic emotional process of overstimulation or overstress. Second type, Addison’s overtrainness, is the consequence of parasympatic inhibition. Between these two, parasympatic or Addison’s is harder to discover. In sport disciplines sympatic type is dominant.

Under normal circumstances, sympatic neural activity is increased as a result of training and amount of few chormones, like adrenaline(epinephrine), noradrenaline(norepinephrine), HGH, cortisol and tyroid, stimulus chormone. Researchers discovered chormones in blood in increased concentrations and concluded that few of these changes are components of normal stress reaction on training.

Furthermore, once body is left for few days without proper recovery, physically and psychologically under too big stress, supercompensation is not further possible. If it comes to stress due to too high-intensive stimulus or due to sudden increase of load on training, body products symptoms that are similar to Basedow disease. These symptoms are very close to the athletes that take part in high intensity activities that are not connected to the endurance(for example sprint). Symptoms are: increased heart rate during rest, less dream, weaker recovery after training, sleep disorder, increased blood pressure in rest, weakened return of blood pressure on beginning stages after training, increased infections rate, decreased maximal outgoing power, decreased performance, weight loss, increased irritability and emotional instability, loss of wish for training and competition, postular hypotensia and increased injury rate.

Biochemical relation between testosterone and cortisole is disordered. Researchers proved that low cortisole production regulation is primary for beginning of testosterone raise that looks for anabolic process. Decrease in testosterone amounts stops testicular excretion possible through the way of increased cortisole ratios or other chormonal mechanisms. Amount of testosterone can return slower to normal basic amounts after serious body training and it is possible that few days may be necessary for return into normal. Ratio can be related to catabolic condition that is reported in Basedow overtrainness syndrome, cause testosterone-cortisole ratio has implications to include anabolic process for recovery and because it can ask for more than one day.

Parasympathetic overtrainness has symptoms that are related to Addison’s disease. Adrenal glands don’t control chormonal concentrations regularly and though chormone amounts are dropping, especially cortisole chormone, like tyroid chormone, HGH and free testosterone.

Addison’s overtrainness is the consequence of too much high volume trainings and it is more usual at athletes that do endurance sports. Like at Basedow’s overtrainness, ability of central nervous system to work is significantly decreased. Some symptoms related to Addison’s overtrainness are progressive anemia, decreased haemoglobine, decreased hematocrytes, need for bigger amount of quality sleep in spite of insomnia is not present, low blood pressure, low rest pulse, low amounts of free testosterone, mood disorder, digestive disorder – all together weakens performance.

"Periodization, theory and methodology of training", Tudor Bompa