Nowdays, much attention is paid to the study of disorders of immune regulation and methods of effective immune correction in athletes. In this regard, the use of specialized sport foods (SSF), containing nutrients with immunomodulatory properties, is of particular relevance in youth sports. The aim of the work is to study the immunomodulating activity of L-carnitine and coenzyme Q10 in junior athletes during the training period. Material and methods. The object of the study were 30 junior athletes (masters of sports and candidates for masters of sports in swimming) aged 14-18 years, including 9 girls and 21 boys. Athletes were divided into 3 groups of 10 people each. Athletes of the 1st and 2nd main groups received L-carnitine (600 mg per day) and coenzyme Q10 (60 mg/day), respectively, for 4 weeks in addition to the basic diet. The dosage of SSF used in the study was 200% of the adequate level of consumption and did not exceed the upper permissible level of consumption. Athletes of the 3rd group (control) received only basic diet without sports' nutrition. Examination of athletes of all groups was performed at the beginning and after 4 weeks of the observation period. Results and discussion. As a result of a comprehensive survey of junior athletes, the positive effect of L-carnitine intake on erythrocyte hemoglobin content (30.2±0.4 vs 28.3±0.3 pg at the beginning) was observed. The relative content of basophilic leukocytes in athletes of the main groups statistically significantly decreased by the end of the observation period: in the L-carnitine group, from 0.64±0.05 to 0.45±0.04%, in the coenzyme Q10 group, from 0.66±0.07 to 0.50±0.04%, which indicated an increase in the body's resistance to allergic reactions. Conclusion. The biomarkers of the immunotropic effect of L-carnitine and coenzyme Q10 are a decrease in the expression of the apoptotic marker CD95/Fas on peripheral blood lymphocytes and suppression of the production of pro-inflammatory cytokines synthesized by Th1-lymphocytes with switching the response to humoral immunity. An evidence base for the effectiveness of the use of L-carnitine and coenzyme Q10 in sports nutrition for restoring immune dysfunction and adaptive potential of junior athletes has been provided. Copyright© GEOTAR-Media Publishing Group.