Basal levels of hormones were mostly normal in athletes with OTS/FOR/NFOR compared with healthy athletes .
Distinctly , stimulation tests , mainly performed in maximal exercise conditions , showed blunted GH and ACTH responses in OTS/FOR/NFOR athletes , whereas cortisol and plasma catecholamines showed conflicting findings and the other hormones responded normally .
Conclusion Basal hormone levels are not good predictor but blunted ACTH and GH responses to stimulation tests may be good predictors of OTS/FOR/NFOR
Background Overtraining syndrome ( OTS ) , functional ( FOR ) and non-functional overreaching ( NFOR ) are conditions diagnosed in athletes with decreased performance and fatigue , triggered by metabolic , immune , hormonal and other dysfunctions and result ed from an imbalance between training stress and proper recovery .
Despite previous descriptions , there is a lack of a review that discloses all hormonal findings in OTS/FOR/NFOR .
The aim of this systematic review is to evaluate whether and which roles hormones play in OTS/FOR/NFOR .
Decreased nocturnal catecholamine excretion: parameter for an overtraining syndrome in athletes?
The effectiveness of  high performance training  should be examined at short intervals in order to recognize overtraining promptly . Field or laboratory tests can usually not be performed with such frequency . Easy-to-measure biological , training-relevant parameters are being sought to use in their place . Since the importance of the sympathetic nervous system for adaptation of stress and the relationship between physical training and the activity of the sympathetic nervous system are well accepted , and since an impairment of the sympathetic nervous system is assumed in an overtraining syndrome , we examined the relevance of nocturnal " basal " urinary excretion of free catecholamines with respect to its practical application : 1 . during a pilot study ( training of road and track cyclists before the 1988 Olympic Games in Seoul ) , 2 . through a 4-week prospect i ve , experimental study in 1989 and 1990 ( middle- and long-distance runners ) , 3 . during the competitive season and winter break of a soccer team between August 1990 and April 1991 . The following hypothesis was made : An overtraining or exhaustion syndrome in athletes may usually be accompanied by at least a 50 % decrease in basal dopamine , noradrenaline and adrenaline excretion . When training is effective or the athletes are not exhausted , the decrease of the excretion rate -- with the exception of dopamine -- is more likely to be lower ( noradrenaline , adrenaline ) . Generalization of these results requires further expansion of the experimental basis
Basal levels of hormones were mostly normal in athletes with OTS/FOR/NFOR compared with healthy athletes .
Distinctly , stimulation tests , mainly performed in maximal exercise conditions , showed blunted GH and ACTH responses in OTS/FOR/NFOR athletes , whereas cortisol and plasma catecholamines showed conflicting findings and the other hormones responded normally .
Conclusion Basal hormone levels are not good predictor but blunted ACTH and GH responses to stimulation tests may be good predictors of OTS/FOR/NFOR
Background Overtraining syndrome ( OTS ) , functional ( FOR ) and non-functional overreaching ( NFOR ) are conditions diagnosed in athletes with decreased performance and fatigue , triggered by metabolic , immune , hormonal and other dysfunctions and result ed from an imbalance between training stress and proper recovery .
Despite previous descriptions , there is a lack of a review that discloses all hormonal findings in OTS/FOR/NFOR .
The aim of this systematic review is to evaluate whether and which roles hormones play in OTS/FOR/NFOR .