In this review, we consider metabolic pathways of energy production from the standpoint of determining the mechanisms of energy supply during intense physical activity and the need to accelerate the process of ATP resynthesis; possible directions of this process intensification are outlined. The most important systems for an athlete to limit his physical performance are the cardiovascular and muscular. That is why we emphasize on energy production in myocardial cells and myocytes. Energy production and energy exchange in cells is carried out by mitochondria, which are the main organelles of energy supply. Functional activity of these organelles is provided by the inner membrane, which contains components of the electron transport chain and ATPase. Physical activity requires ATP resynthesis, which is provided by different types of energyreleased reactions. An important part of our review reveals the analysis of data on the mitochondria themselves, which are key determinants of the functional state of the body’s cells during physical activity. Functional consequences of the changes in mitochondrial structure are of quite importance, especially associated with different configurations of mitochondria and mitochondrium − increasing the number of organelles and crystal density, normalization of the structural and functional state of the inner membrane and its protection from oxidative stress which is inherent in the intense physical activity. Oxidative stress and working hypoxia are a very common cause of further metabolic disorders, even before the formation of hypertrophy of chronic physical exertion, when you have to remove an athlete from the training process. In general, numerous metabolic processes in the myocardium, which are inherent in intense physical activity, undergo negative changes with further activation of athletes. One of the ways to correct energy deficiency caused by prolonged and intense physical activity should be the use of exogenous or endogenous substances involved in energy metabolism.