Striving to achieve the goals of the training process with the irrational use of physical activity can lead to a decrease in the adaptive and reserve capabilities of the athlete. The development of changes in the endocrine, cardiovascular and central nervous systems may result in the development of overtraining syndrome. There is no unified approach to the definition, diagnosis, treatment and prevention of overtraining syndrome in the literature up to the present day. The endocrine aspects of the development of the overtraining syndrome are not sufficiently studied. In particular, there is no clear understanding of the degree of involvement of various hormonal mechanisms in its pathogenesis and ideas about the possibilities of using hormone levels to diagnose this condition. The purpose of this publication is to summarize and systematize the available concepts regarding the endocrine aspects of the overtraining syndrome.

Electrocardiography (ECG) is the most commonly used method of instrumental screening, which can detect phenomena in athletes that are not typical of individuals in the general population. Such electrophysiological phenomena as sinus bradycardia, sinus arrhythmia, functional atrioventricular (AV) block, etc., can lead to errors in the diagnosis and tactics in the athlete. The most well-known algorithm for the interpretation of Domenico Corrado and Antonio Pelliccia (2010) is now extended and supplemented by the criteria of Shrarma S. and Drezner J. A., (2017). Along with the changes previously adopted, arising under the influence of increased vagal and morphological remodeling, paid attention to racial and age influences.