“…The listed criteria for differentiating the training process are characterized by pedagogical, morphological, and psychological factors. Specialists in the theory and physiology of sports understand that the focus of the training process is the improvement of morpho-functional characteristics [12,13,16], cardiovascular and respiratory systems [6,7], nervous systems [3,4,5] and mechanisms providing muscle activity [9,14]. However, insufficient attention has been paid to the stable biological properties of load differentiation.…”