Dr. Med., Professor A.L. Korepanov¹
Dr. Hab., Professor O.N. Golovko¹
PhD, Associate Professor V.A. Ley^1
1Sevastopol State University, Sevastopol

Keywords: adolescent boys, young men, adaptive potential, cardiovascular system.

Introduction. The growing number of functional disorders of cardiac activity in adolescents and young men determines the relevance of studying the adaptive reserves of the heart [1].
The aim of the study was to evaluate the functional reserves of the cardiovascular system of adolescent boys and male students.
Methodology and organization of research. 36 people took part in the scientific work, which was divided into 3 groups of 12 people each. The first group consisted of boys aged 13-14, the second and third – first and fifth year students, respectively. An ECG, phonocardiogram, and sphygmogram of the carotid artery were recorded. The parameters of the phase structure of the cardiac cycle, heart rate variability, indices and adaptive potential of the cardiovascular system were determined.
The results of the study and their discussion. Significant differences in the functional parameters of the heart between adolescents and young students have been revealed. Senior students have a decrease in cardiac contractility, which is confirmed by a significant (p<0.05) increase in the duration of the isometric contraction phase in fifth-year students compared with adolescents (32.6±1.4 ms and 27.1±1.3 ms, respectively), as well as a higher index of myocardial tension (25.7±1.1% and 23.4±1.1%, respectively) and the level of cardiac mobilization (1.66±0.06 cu and 1.41±0.06 CU, respectively). The adaptive potential of the heart (the higher the digital value of this indicator, the lower the adaptive capabilities) in fifth-year students was 1.9±0.04 units and was significantly (p<0.05) lower than in adolescents (1.65±0.03 units) and first-year students (1.68±0.05 units). The described dynamics of adaptive potential reflects a decrease in the adaptive resources of the cardiovascular system of students during their studies at the university. The level of stress experienced was significantly (p<0.05) higher in senior students (1.72±0.07 units) than in schoolchildren (1.58±0.04 units). The variation range in adolescents, first-year and fifth-year students was 0.31±0.01 s, 0.26±0.01 s and 0.25±0.02 s, respectively, and was significantly (p<0.05) lower in first- and fifth-year students than in adolescents. The standard deviation in adolescents, first-year and fifth-year students was 60.4±1.3 ms, 55.9±1.2 ms and 52.5±1.2 ms, respectively, and was significantly (p<0.05) lower in first- and fifth-year students than in adolescents, as well as lower in fifth-year students than in first-year students. The described dynamics of the variation range and standard deviation reflect a decrease in the influence of the parasympathetic nervous system on the heart rate during university studies.
Conclusions. A decrease in the adaptive resources of the heart among students, compared with high school students, has been established. The negative dynamics of the functional parameters of the cardiovascular system during university studies was noted. The data obtained will be used in student exercise optimization programs.

Литература

1. Korepanov A.L. Funktsionalnye pokazateli deyatelnosti serdtsa u podrostkov s raznymi tempami fizicheskogo razvitiya [Functional indices of cardiac perdormance in adolescents with different rates of physical development]. Teoriya i praktika fizicheskoy kultury. 2016. No. 12. Pp. 49-51.