Аннотация:A comparative study of the state of the cardiovascular systems of adolescents not engaged in sports and young athletes of the same age has been performed. According to the indices recorded in the resting state, a relative lag of the functional development of the systems of autonomic control of the cardiovascular system was shown for adolescent nonathletes at an age of 13–14 years as compared with young athletes. This lag is compensated by the age of 15–16 years, but the adequate level of autonomic activity is reached through the activation of central regulatory mechanisms (sympathetic and humoral), with a relatively low contribution of the peripheral vagal and baroreflex mechanisms. This conclusion is confirmed by the results of assessment of the reactivity of the cardiovascular system of adolescents with different levels of motor activity in a functional test with limited pulmonary ventilation.