Applicant S.A. Sherstyuk¹
Dr. Med., Professor L.V. Kapilevich^1,2
PhD, Associate Professor A.A. Sherstyuk^3
1National Research Tomsk State University, Tomsk
²Siberian State Medical University, Tomsk
³Siberian State University of Physical Culture and Sport, Omsk

Keywords: adaptation, myocardium, transmitral flow, remodelling, physical load, elite athletes.

Introduction.  Body adaptation mechanisms to physical activity are traditionally considered from the integrated approach position [8]. In the sport of setting records, the assessment of the cardiovascular system (CVS) adaptation includes systolic and diastolic blood circulation, cardiac activity autonomic regulation of indicators. Vegetative (neurogumoral) regulation reflects possibilities of influence of the sympathetic and parasympathetic nervous system taking into account humoral factors’ action on heart rhythm [3].

The assessment of muscular activity metabolic changes reflects readiness of CVS to glycolytic loads, with glycolytic capacity’s determination and its relationship with morphometric and hemodynamic indices of sports heart adapted to load [5,6].

Objective of the research was to study hemodynamic performance characteristics of elite athletes taking into account autonomic regulation when performing aerobic and anaerobic loads.

Methods and structure of the study. The study involved 51 qualified athletes: 17 handball players aged 18-29 years with the sports experience from 10 to 15 years, and 34 cyclists (track) aged 22-26 years with the sports experience from 7 to 10 years. Both groups were experimental (EG -1 and EG-2). The study also involved a control group (CG), which consisted of 17 healthy young people who were not actively involved in sports, aged 18-29 years.

The myocardial systolic diastolic parameters were estimated using ECHO dopplercardiography (ECHO-KG). Diagnostic equipment was used: ultrasonic scanners "GE VIVID E 95," "GE VIVID I." Parameters of left ventricular remodeling (LV) [2] were measured: left ventricular myocardial mass (LVMM) g; LVMM index (iLVMM), g/m2. Normal LV geometry was considered to be relative wall thickness (RWT) < 0.42-0.45 at normal LV parameters iLVMM less than 115 g/m2 in men, for women - less than 95 g/m2 [2.6]. To evaluate the hemodynamic parameters of the diastolic function, transmitral blood flow indices were used: maximum speed of early diastolic filling (Peak E), m/s; maximum atrial system filling rate (Peak A), m/s; ratio of peaks E and A (E/A) u.e.; LV isovolumic relaxation time (IVRT) in milliseconds (ms); ejection time (ET) (in ms).

In order to study the heart rate variability (HRV) at rest on the VNS-micro device (Company "Neurosoft" Russia), measurements in the group of qualified cyclists (p = 34) were made. Time and spectral (frequency) parameters of HRV reflecting the state of athletes’ rhythm’s autonomic regulation are analyzed.

In addition, the study determined the difference in the level of total endurance (Cooper's test) of athletes and those not involved in sports, and the morphometric and hemodynamic heart indicators [8]. To identify the level of special operability and glycolytic capacity, the test "Running 300 meters" (s) was carried out as recommended in the training program for qualified handball players of the Republic of Hungary [6].

Results and discussion. Cardiac myocardial remodeling parameters belonged to the normal type of LV myocardial geometry in all the groups examined. Statistically significant differences between athletes and non-athletes do not go beyond the physiological norm. With a competently constructed training process, athletes can achieve high qualification without violating the parameters of normal cardiac geometry. This statement is supported by the results of the data from ECHO-KG, analysis of the influence of sympathetic and parasympathetic departments of ANS, and the results of pedagogical testing [5.6]. Athletes with the predominance of classical components of the sports heart at rest can be in the best form while maintaining the parameters of normal LV geometry for a long time [2].

Table 1. Statistical and spectral indicators of HRV (Xavg ± SE)

In order to assess neurogumoral influences on the cardiac rhythm regulation, cardiac rhythm variability indices (HRV), as well as cardiac mechanics remodeling index in diastole [4] were investigated. Measures of heart rate variability of individuals are EG 2 shown in comparison with measures of average data for young men. Data were obtained as part of the work of the experimental "platform" of biomedical support of cyclic athletes (presented in Table 1) [7].

Variability parameters make it possible to notice the predominant parasympathetic influence on the generating of sinus rhythm pulses with uniform exposure to humoral and sympathetic components. As seen from the given data, preferential influence of the parasympathetic nervous system on the generating of the sinus node’s pulses makes it possible to consider group of examined athletes being sufficiently ready for high intensity loads and high sports results’ achievement [2].

The ratio of transmission blood flow E/A, in persons not engaged in sports, is inferior to athletes at an accurate level. In the indicators IVRT and ET (ms.), an accurate advantage of athletes is also defined [3]. The time-determining values for the duration of diastole are shown in Table 2.

Table 2. Blood flow rates at examined individuals (Xavg ± SE)

* - accurate of differences with the control group (р<0,05)

The obtained results of transmitral blood flow can be interpreted as a hemodynamic marker of a sports heart with a "Supernormal" configuration of transmitral blood flow at normal LV geometry [5.6]. As our studies showed, when evaluating general and special performance, this indicator reflects the athlete's fitness for various loads, as well as determines the level of anaerobic glycolytic capacity. The latter was confirmed by the results of testing individuals EG1 and CG (when performing the tasks "Cooper Test" (m) and "Running 300 m" (s)). According to Cooper's test results, athletes showed a reliable advantage of more than 680 m compared to CG persons [5]. The comparison in the test "Running 300 m" (s) EG1 and CG was considered as incorrect, since the test is associated with the manifestation of glycolytic (high-speed) endurance. Athletes showed anaerobic glycolytic capacity at lactate titer 9-11 mmol/l, which was observed for 3 min of recovery after test [1.5].

Figure 1. The ratio of E/A flow rates in the form of «Supernormal» remodeling of diastolic filling [4].

Under physiological conditions (60-85%) of blood, it enters by transit from pulmonary veins to the phase of passive early diastolic filling, and (15-30%) enters the period of atrial systole. In conditions of rhythm deceleration, there is a smaller contribution of atrial contraction to the late diastole component. Since the contribution of the atrial systole to the late diastole component [3] also increases with an increase in HR, diastolic parameters with an increase in HR lose their economy, and the time to restore the LV myocrade. This can be seen from the parameters of diastole of KG persons, which in turn is manifested by a decrease in the transmitral E/A ratio less than 2.0 cu (average value of 1.43 cu) [5.6].

Based on the HR values in EG 1 and 2 (Table 1), it can be concluded that with the predominance of the parasympathetic component on the generation of sinus node pulses, the time of early and late diastole increases, forming a time reserve for myocardial recovery before subsequent effective reduction. With the previously noted values of HR EG 1 and 2, it is obvious that the diastole of the sports heart, represented by the "Super Normal" remodeling of cardiac mechanics [4], under the influence of the parasympathetic regulation link [2], forms a reserve for different loads types. That is confirmed by us as a result of tests with determination of level of general (aerobic) and special (anaerobic glycolytic) performance in qualified athletes [5, 6].

Conclusions:

1. The parasympathetic contribution to the rhythm regulation, with the "Super Normal" version of cardiac mechanics remodeling is the indicator of fitness for aerobic and anaerobic loads with the highest glycolytic capacitance result;

2. Vegetative regulation parameters, myocardial geometry and transmitral blood flow indicators are promising application points of both non-drug and legal pharmacological means of recovery in sports.

References

1. Butova O.A., Masalov S.V. Adaptation to physical activity: anaerobic metabolism of muscle tissue. Vestnik Nizhegorodskogo universiteta N.I. Lobachevskogo. 2011. No. 1. pp. 123–128.
2. Gorbenko A.V. Athletic heart: norm or pathology. Patologiya krovoobrashcheniya i kardikhirurgiya. 2020. V. 24. No. 2. pp. 16–25.
3. Kovalenko V.N., Yabluchanskiy N.I. Heart physiology (physiology, changes in pathological conditions). VIsn. Khark. nats. un-ta. 2003. No. 597.pp. 1-14.
4. Shahnovich P.G. Diastolic myocardial dysfunction: echocardiographic phenomenon or type of heart failure?. Vestnik Rossiyskoy voenno-meditsinskoy akademii. 2015. 3 (51). pp. 54–57.
5. Sherstyuk S.A. Experimental substantiation of reserve adaptive capabilities of physiologically athletic heart in terms of transmitral blood flow in elite athletes]. International research journal. 2020. No. 7 (97), V. 2. pp. 57–61.
6. Sherstyuk S.A. New aspects of assessment of adaptation to physical activity: physiologically athletic heart and transmitral blood flow in conditions of aerobic-anaerobic metabolism of muscle activity. International research journal. 2020. No. 8 (98). V. 2. pp. 80–86.
7. Sherstyuk S.A., Konovalov V.N., Sherstyuk M.A. Biomedical “foundation” as basis for ensuring elite cyclic athletes’ training. Medical support of elite sports. Proceedings XII international scientific conference on the state and prospects for development of medicine in elite sports. Moscow, 2018. pp. 128-130.
8. Krivoshchekov S.G., Balioz N.V., Nekipelova N.V., Kapilevich L.V. Age, gender, and individually-typological features of reaction to sharp hypoxic influence. Human Physiology, 2014. V.40, no. 6. pp.613-622.

Corresponding author: fizkult@teoriya.ru

Abstract

Objective of the study was to identify hemodynamic features of the physical working capacity of highly-skilled athletes under aerobic and anaerobic physical loads taking into account the type of autonomic regulation.

Methods and structure of the study. Sampled for the study were 51 qualified athletes: 17 handball players aged 18-29 years with 10-15 years of sports experience; 34 racing cyclists aged 22-26 years with 7-10 years of sports experience. Both groups were taken as the Experimental ones (EG-1 and EG-2). The study also involved the Control Group (CG), which consisted of 17 healthy young males aged 18-29 years who were not actively involved in sports. The systolic and diastolic ventricular function was evaluated by Doppler echocardiography performed using the ultrasonic scanners "GEVIVIDE 95", "GEVIVIDI". The left ventricular remodelling indices were measured. The hemodynamic parameters of the diastolic function were assessed based on the transmitral flow indices. The racing cyclists (n=34) were subjected to the heart rate variability test (at rest) using the "VNS-Micro" device. We also analyzed the temporal and spectral (frequency) parameters of HRV that reflect the state of autonomic regulation in the athletes. In addition, we determined the differences in the overall endurance rates (Cooper’s test) between the athletes and non-athletes, as well as the cardiac wall motion and cardiac hemodynamic indices.

Results and conclusions. The diastolic indicators of the transmitral flow (E/A, IVRT, ET) at rest can be considered as predictive measures in determining the exercise capacity (both aerobic and anaerobic) of an individual. In terms of the properly organized training process, the athletes’ autonomic regulation, left ventricular geometry, and hemodynamic parameters of the diastolic function at rest did not go beyond the limits of the physiological norm. At the same time, the athletes’ physical load tolerance was significantly higher than that of the non-athletes.