Assessment of the functional state of the body of highly qualified swimmers based on the analysis of correlations and dynamics of indicators of the morphological composition of the blood after the stress test

Objective: to evaluate the interactions and dynamics of hematological parameters before and after exercise testing in high performance sprint swimmers. Materials and methods: 16 male ( n = 8) and female ( n = 8) high‑performance swimmers (19.31 ± 1.08 years) were studied. Venous blood samples were taken before and after exercise. Erythrocyte, leukocyte and platelet indices were assessed. Physical activity was a stepwise incremental test on an ergometer until failure. Results: a significant variation in hematological blood parameters was found in the swimmers both at rest and after exercise. In both men and women an increase in haematocrit was observed with an increase in erythrocyte count. The increase in erythrocyte indices was accompanied by a decrease in platelet indices in female athletes. In males, inverse relationships were mainly found only between the leukocyte blood indices. In female athletes, the number of direct and feedback correlations after exercise remained at the same level as at rest, whereas in men the number of direct correlations decreased after exercise. Conclusion: the training effect in females was manifested by the formation of several interdependencies between blood parameters, indicating a better adaptation of the blood system to the training load. In men, on the other hand, the pattern of relationships indicates the presence of tension in the regulatory mechanisms.