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 .
Catecholamine responses to short-term high-intensity resistance exercise overtraining.
Seventeen weight-trained males were divided into an  overtraining group [ OT ; n = 11 ; age = 22.0 + /- 0.9 ( SE ) yr ] that weight trained their legs daily for 2 wk with 100 % 1 repetition maximum relative intensity on a squat machine and a control group ( n = 6 ; age = 23.7 + /- 2.4 yr )  that exercised 1 day/wk with low relative intensity ( 50 % 1 repetition maximum ) . Test batteries including strength assessment s and resting and exercise-induced concentrations of epinephrine and norepinephrine were conducted at the beginning , middle , and end ( tests 1 - 3 , respectively ) of the study . Strength capabilities decreased by test 3 for the OT group ( P < 0.05 ) . Resting catecholamine concentrations did not change for either group during the study , whereas exercise-induced concentrations of both epinephrine ( test 1 = 3,407.9 + /- 666.6 pmol/l , test 2 = 7,563.7 + /- 1,210.6 pmol/l , test 3 = 6,931.6 + /- 919.3 pmol/l ) and norepinephrine ( test 1 = 42.9 + /- 7.4 nmol/l , test 2 = 70.0 + /- 8.8 nmol/l , test 3 = 85.2 + /- 14.5 nmol/l ) significantly increased by tests 2 and 3 for only the OT group . Correlation coefficients suggested decreased responsitivity of skeletal muscle to sympathetic nervous system activity . It appears that altered exercise-induced sympathetic nervous system activity accompanies high relative intensity resistance exercise overtraining and may be among the initial responses to the onset of the previously theoretical sympathetic overtraining syndrome
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 .