Under high-intensity loads, the athlete's bodies take place a number of biochemical reactions and physiological processes that can lead to hyperbilirubinemia. The factors that can initiate the onset of this phenomenon include the syndrome of micro-damage muscle, violation of the integrity of erythrocyte membranes, decreased blood pH, malnutrition and increase oxygen demand of the body. Degree of expression of manifestations of physiological bilirubinemia depends on the level of adaptation of the athlete to the physical activities offered. Hyperbilirubinemia in athletes can be one of the components of the deterioration of the functional state, forming the symptoms of endogenous intoxication. The relevance of this problem in sport lies in the relatively low detection rate of hyperbilirubinemia due to the lack of regular screening studies. However, in drawing up a plan of nutritional- metabolic support for training and competitive activity and recovery measures, must not only the individual reaction of the athlete body to physical activity, but also the severity of shifts in the indicators of bilirubin metabolism and their ratio. The article describes the reasons for the increase in bilirubin levels, which can be caused by both the effect of physical activity and by the presence of pathological processes in athletes. The factors influencing the blood serum’s bilirubin content are also highlighted, which include the state of erythrocyte cell membranes and the rate of hemoglobin destruction, the functional state of the liver, the specifics of physical loads and the use of ergogenic pharmacological agents by athletes. Particular accent has been placed on the illumination of hereditary hyperbilirubinemias, which may have been detected at the stage of selection of athletes. The most common phenomenon is Gilbert's syndrome, which occurs in 2-5% of cases in the general population, is characterized in the clinic by a benign flow and is manifested by episodes of jaundice and an increase in total bilirubin content to moderate values due to indirect. The frequency of detection of hyperbilirubinemias in the population of athletes is 4.68%, among which Gilbert's disease accounts for almost half (48.7%). Conclusion. The work highlighted the pathogenesis and diagnostic algorithm of Gilbert's disease, and also emphasized that its drug prevention and correction in athletes to maintain functional and physical fitness should be carried out taking into account anti-doping rules, which requires upon diagnosis timely receipt of a therapeutic exclusion
