The study of the processes occurring in the body under the influence of intense physical exertion, in order to increase the efficiency of the training process and the performance of athletes, is an important issue in the physiology of sports. It is known that the strength, speed, endurance and other morphofunctional features of a person are genetically determined. Therefore, the actual direction of research is the establishment of a spectrum of polymorphic genetic variants of genes associated with a predisposition to perform physical activities of varying intensity, as well as their phenotypic manifestation in professional activity.
However, despite the active search for genetic markers in sports with the use of modern high-tech technologies, it has not yet been possible to identify universal genes associated strictly with certain physical qualities. Perhaps, there is a number of factors that affect gene activity. Therefore, the purpose of the literature review is to search and analyze possible causes that can influence the activity of genes, for example, the most studied angiotensin-converting enzyme (ACE) gene associated with the development of specialized physical qualities in athletes.