Dr.Biol., Professor A.Kh. Talibov¹
PhD, Associate Professor V.A. Kuvanov²
Ya.A. Kuvanov^2
1Lesgaft National State University of Physical Education, Sport and Health, St. Petersburg
²Saint-Petersburg Mining University, Saint-Petersburg

 

Keywords: blood circulation, weightlifters, echocardiography, cardiovascular system, physical loads.

Background. The dynamics of cardiac activity during sports activities are determined by the considerable, often extreme, training- and competition-specific workloads, as well as the nature of exercises. Among the factors contributing to the bodily adaptation to strenuous muscular activity, a major role is played by the circulatory apparatus, which functional capacity is determined by both the actual state of the cardiovascular system (its ability to strengthen activity under physical loads) and the level of functioning of all the regulatory links. The functional mobility of the circulatory apparatus depends not only on the speed of switching of various body systems but also on the synchronicity in their activity, as well as on the recovery rate [3, 7].

Objective of the study was to identify changes in athletes’ cardiovascular system parameters under the influence of physical loads and identify the peculiarities of the state of adaptation mechanisms.

Methods and structure of the study. The study involved 165 highly skilled athletes involved in regular weightlifting practices. The testing included echocardiography using Acuson Sequoia device in M-mode. We determined the dimensions of the left ventricle, as well as stroke volume and circumferential fiber shortening velocity as a criterion of its contractile function.

The study was carried out in the period from 2008 through 2018.

Results and discussion. With regard to excessive physical loads as a cause of development of pathological conditions of the cardiovascular system, it should be emphasized that in elite sports, the level of training loads is determined primarily by the modern level of sports achievements in a certain sport [5]. Recent years have shown a clear upward trend in the training and competitive loads in sports, which results in myocardial overtension, functional and morphological disorders of the cardiovascular system [2].

In assessing the functional state of the circulatory organs in athletes, insufficient attention is paid to the study of the central hemodynamics through echocardiography [4]. It is known, however, that the echocardiographic indicators provide a good overview of the nature of adaptive responses of the cardiovascular system to physical loads, physical fitness progress, and emergence of premorbid and pathological conditions in athletes [6].

Echocardiography has taken a firm place in the range of non-invasive cardiovascular functionality research methods, as it provides unique information compared to other methods. However, the literature data on the comparative studies of the process of adaptation of athletes' hearts by echocardiography are contradictory, and the results of evaluation of the detected changes are ambiguous [8].

The statistically significant seasonal changes related to the dynamics of training loads were noted in the heart of the middle- and long-distance runners, swimmers, and football players [1]. Echocardiography helped obtain the data were obtained on the dynamics of seasonal changes in the heart of the weightlifters [8].

The echocardiographic studies were conducted in four stages: at the beginning and at the end of the general preparatory and special preparatory stages, preparatory period, and main competitions of the annual training cycle (see Table 1). The hemodynamic indicators tended to improve during the preparatory period. This was due to the enhanced functional state of various systems of the weightlifters’ body achieved through intensive training loads. It was found that the training loads of the preparatory stage, focused on the comprehensive development of physical fitness, cause a statistically significant (p<0.05) increase in the stroke volume of the left ventricle - by 35%. The circumferential fiber shortening velocity of the left ventricle was 30%. The data indicate a good level of adaptation of cardiovascular system to the applied training loads and physical fitness progress of the weightlifters. It was also revealed that the stroke volume of the left ventricle and circumferential fiber shortening velocity of the left ventricle are the most informative indicators that reflect the performance and functional state of cardiovascular system under significant physical loads.

We believe an increase in the stroke volume of the left ventricle is a favorable factor in the cardiac activity, as it indirectly indicates that the intensification of cardiac activity is related to the improvement of the contractive function of myocardium rather than the heart rate increase.

 

Table 1. Dynamics of cardiovascular system indicators in athletes within training cycle according to echocardiography (x Sx , n=165) (x±Sx , n=165)

 

The more economical work of the heart in the weightlifters at this stage was also evidenced by the 25% increase in the left ventricular ejection fraction, which ultimately determined the efficiency of the cardiac cycle. In the competitive period, a decrease in the volume and an increase in the intensity of training loads were accompanied by the stabilization of the central hemodynamic indices. This cardiovascular functionality level was maintained throughout the entire competitive period with an increase in the left ventricular ejection fraction by 33%(р<0,05), and the velocity of diastolic flow through the mitral valve - by 35% (р<0,05). The increase in the stroke volume and velocity of circumferential fiber shortening of the left ventricle that occurred at the end of the study, as compared to the results obtained at the beginning of the study, was due to the improved functioning of the left ventricle. The results of evaluation of the cardiovascular functionality made it possible to adjust the training process. To summarize the findings, it should be emphasized that there were adaptive changes in the cardiovascular system of the weightlifters that led to the improvement of the contractile function of myocardium and economization of cardiac activity at rest and under physical loads.

Conclusions. The identification and analysis of the factors influencing the athletic performance of the weightlifters made it possible to individualize the training modes and thus improve the competitive results. The studies showed significant variations in the exercise performance process associated with the weightlifters’ individual characteristics, which requires an individual approach to the content and methods of training of athletes of various weight categories. Echocardiography is an effective non-invasive method for estimating the geometry of the left ventricle and controlling the dynamics of hemodynamic changes under intense training loads in the annual training cycle. Based on these data, it becomes possible to adjust the training process so that to prevent the development of prepathological conditions and improve athletic performance.

 

References

1. Belotserkovskiy Z.B., Lyubina B.G. Cardiac activity and functional fitness in athletes (norm and atypical changes under adaptation to physical loads). Moscow: Sovetskiy sport publ., 2012, P. 548: il.

2. Volkov A.V., Panchenko I.A., Babchenko A.P. Training load volume and goal as key factors of performance control in judo. Teoriya i praktika fiz. kultury. 2017. no. 7. pp. 66-68.

3. Zinoviev N.A., Gromov M.M., Bobrov I.V. Benefits of blood flow restriction trainings for Alpine skiing sport. Teoriya i praktika fiz. kultury. 2019. no. 4. pp. 12-15.

4. Romanov Yu.N. Assessment of cardiorespiratory system functionality in kickboxer students in transitional period of mesocycle. Teoriya i praktika fiz. kultury. 2012. no. 1. pp. 25-28.

5. Rudenko G.V., Dubrovskaya Yu.A., Bobrov I.V. Individual psychophysiological potential test model. Teoriya i praktika fiz. kultury, 2018, no. 4, pp. 8-10.

6. Sysoev A.V., Popova I.E. Functional features of cardiorespiratory system of female basketballers of different ages. Teoriya i praktika fiz. kultury. 2012. no. 5. pp. 31-34.

7. Talibov A.Kh., Gushchina N.V., Lyashchenko O.V., et al. Dynamics of athletes' health and physical development in long-term training process . Teoriya i praktika fiz. kultury. 2019. no. 4. pp. 102-104.

8. Talibov A.Kh. Functional cardiology of healthy person when adapting to systematic physical activity. Doct. diss.. (Biol.). St. Petersburg, 2017. 322 p.

 

Corresponding author: kuwanov@mail.ru

 

Abstract

Objective of the study was to identify changes in athletes’ cardiovascular system parameters under the influence of physical loads and identify the peculiarities of the state of adaptation mechanisms.

Methods and structure of the study. The study involved 165 highly skilled athletes involved in regular weightlifting practices. The testing included echocardiography using "Acuson-Sequoia" device in M-mode. We determined the dimensions of the left ventricle, as well as stroke volume and circumferential fiber shortening velocity.

Results and conclusions. It was found that the training loads of preparatory stage, focused on the comprehensive development of physical fitness, cause a statistically significant (p<0.05) increase in the stroke volume of the left ventricle - by 35%. The circumferential fiber shortening velocity of the left ventricle was 30%. The data indicate a good level of adaptation of cardiovascular system to the applied training loads. It was also revealed that the stroke volume of the left ventricle and circumferential fiber shortening velocity of the left ventricle are the most informative indicators that reflect the performance and functional state of cardiovascular system under significant physical loads. An increase in the stroke volume of the left ventricle is a favorable factor in the cardiac activity. In the competitive period, a decrease in the volume and an increase in the intensity of training loads were accompanied by the stabilization of the central hemodynamic indices. This level of functioning of the cardiovascular system was maintained throughout the entire competitive period with an increase in the left ventricular ejection fraction by 33%, and the velocity of diastolic flow through the mitral valve - by 35%.

The studies showed significant variations in the exercise performance process associated with the weightlifters’ individual characteristics, which requires an individual approach to the contents and methods of training of athletes of various weight categories.