ASSESSMENT OF THE COMPONENTS OF THE OXYGEN TRANSPORT SYSTEM AND THE CONTRIBUTION OF THE HORMONAL LINK TO PROVISION OF PHYSICAL ENDURANCE IN ATHLETES OF VARIOUS SPORTS

The purpose of the research was to assess the contribution of hematological, hemodynamic and hormonal parameters to ensuring cardiorespiratory endurance of athletes specializing in different sports.

Materials and research methods. The study involved 60 young men aged 18 to 22 years. The surveyed population was divided into three groups. The first group included sportsmen of team sports (lapta, hockey) (n=22). The second group consisted of athletes of strength and speed-strength sports (weightlifting, martial arts) (n=18). The comparison group is represented by students who do not go in for sports (n=20). Qualification of athletes – from the 1st category to candidates for the master of sports. Physical endurance was assessed by calculating the cardiorespiratory index (CI) in the adynamic (CIadin) and dynamic (CIdin) phases. Basic hematological parameters were determined, as well as serum concentrations of thyroid-stimulating hormone (TSH), free thyroxine (free T4), and cortisol.

Research results. An increase in the level of cortisol in the blood of athletes of both groups was established in comparison with its level in physically inactive individuals. Using factor analysis, it was shown that the body's resistance to physical stress, both in the control group and in athletes specializing in different sports, correlated with an increase in the thyroxine concentration in the blood. In team sports athletes, exercise tolerance is directly proportional to the content of hemoglobin and erythrocytes in the blood, and initial physical endurance (CIadin) is related to the level of cortisol in the blood.

Conclusion. Tolerance to physical activity, regardless of the type of sports activity and in its absence, is determined by the level of thyroxine in the blood. In team sports athletes, physical endurance is controlled by the functional activity of various parts of the body's oxygen transport system and the level of cortisol in the blood plasma.

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