S.S. Grechishkina, Ph.D.
A.V. Shakhanova, professor, Dr.Biol.
M.N. Silant'ev, associate professor, Ph.D.
A.A. Kuz'min, Ph.D.
Adyghe State University, Maikop

Keywords: heart rate variability, cardiorespiratory system, respiratory system, students, basketball.

Introduction. Today's progressing restricted mobility contradicts human biological origin, interrupting the functioning of different systems of the body, and thus provoking a decrease of working capacity and deterioration of health. At the modern stage of development of the Russian society, sport is the main constituent of the social and national health preservation policy. "The main direction is development of physical culture and sport, especially among young people. Under such conditions, it is obvious that mass physical education needs to be developed, especially among students. The goals of team sports clubs include all-round physical development and enhancement of physical fitness [1, 2]. Team sports are most popular among students. To train and compete in team sports an athlete needs to perform lots of speed-strength and sole-weight exercises and have high level of general and speed endurance. In mass sport, training and rest modes are defined by the specified university educational conditions rather than by a trainer, as is in the case of professional athletes. The loads in sports clubs are applied to provoke changes complying only with the phase of enhancement of non-specific tolerance of the body [5].

A system approach is required to consider the fundamental problem of adaptation physiology. In addition to the cardiovascular system, the functional adaptive system that provides final athletic performance includes the respiratory system as an adaptive-resource component of the body, which is essential for homeostasis [2]. In terms of the above, it is of great interest to study the effect of basketball training sessions on functional-adaptive capabilities of the cardiorespiratory system of students training in a basketball club [3, 5].

Materials and methods. The research was conducted with 2nd-4th-year students of non-sports faculties practicing basketball in sports clubs. A total of 25 unrated basketball players with 3-4 years' sport experience were examined. The control group consisted of 35 healthy 2nd-4th-year students of the Faculty of Natural Sciences engaged in traditional regimented motor activity (2 hrs of physical education classes per week). The total number of the subjects amounted to 60 people (young males) aged 18-21 years, which according to the age periodization specified by the Institute of Developmental Physiology of the Russian Academy of Education (1965), corresponds to the adolescent period.

The HRV (heart rate variability) wave structure was studied using the hardware-software complex "Poly-Spectrum-12" ("Neurosoft", Ivanovo town) in the prone position for 5 minutes and in the active orthostatic test in the standing position for 6 minutes, in compliance with the requirements provided by the "International Standard" (Circulation…1996; 93:1043-1065) for short records. The obtained rhythmograms were controlled manually to avoid possible artifacts. The time analysis indices included SDNN, RMSSD, PNN50, measured in ms, and CV and рNN50, measured in percentage.

The spectrum analysis implied the VLF-, LF-, HF-wave power measurement in the spectrum of heart rate variability as a percentage of the spectrum total power (TP), which reflects the relative contribution of each component to the total amplitude of heart rate oscillations (Shlyk, Pseunok, Solodkov, Shakhanova, Kuz'min). The periodic oscillations in the sinus rate were characterized based on the spectrum analysis of HRV [2].

The external respiration characteristics were studied using the computer complex "Spiro-Spectrum" by Neurosoft (Ivanovo town). The reserve and functional capacities of respiratory adaptation were determined by measuring: vital capacity (VC), functional vital capacity (FVC), maximum breathing capacity (MBC), tidal volume (TV), respiration rate (RR), inspiratory reserve volume (IRV), expiratory reserve volume (ERV).

The exercises applied in basketball sports clubs throughout the training period were as follows: conditioning (10-15% of total hours), technical (25-30%), tactical and game (60-65%) training sessions. In pre-season, 75-80% of the time was spent for conditioning exercises, while at the second stage of the pre-season only technical and tactical training sessions were conducted.

Results and discussion.  The best balance at rest was observed in basketball players, when the HF-waves prevailed in the heart rate regulation spectrum (36.2±6.2 % vs. 27.7±5.2 % in those not doing sports, р£0.05), their power was a marker of vagal effects on the heart [4, 9]. The RMSSD indicator of the autonomous regulation activity, was also indicative of the increase of the parasympathetic tone. Higher level of the VLF-waves (32.7±3.9% in basketball players vs. 25.6±7.3% in non-athletes, р£0.05), indicating the cerebral ergotropic effect, may be related to high emotional background of the sport game. The fast (HF) and slow (LF and VLF) wave ratio inherent in the students not doing sports testified to a great effect of the sympathetic nervous system on the heart rate, which proves lower regulatory and adaptive status of the body of students compared with basketball players.

Almost all students not doing sports had the increased control centralization of the heart rate, which lowered the lability of the regulatory and adaptive systems under physical and educational loads.

The economization of the functions of the cardiovascular system at rest dectected in basketball players was due to high activity of the parasympathetic nervous system (high values of HF, TP, RMSSD, SDNN) and a decrease in the cerebral ergotropic effect against the background of the low heart rate, which, according to R.M. Baevsky [2], is an indicator of the substantial adaptive potential of the cardiovascular system. Based on the mentioned facts, it is fair to say that optimization in the heart rate regulation in student basketball players is the result of regular exercises, as such consistency between the central and autonomous regulation circuits was not observed among students not doing sports. This agrees with the concepts of the adaptive-trophic effects of vagal protection of the heart, which provide optimum oxygen supply of an athlete's body at rest and recovery after loads, economization of the cardiovascular system functions [4, 5].

Generally, the parasympathetic regulation prevails in basketball training, which causes economization of physiological functions and reduced physiological "penalty" for adaptive result compared with students not involved in sports.

VC, which characterized endurance and condition level of the respiratory muscles, in students training in basketball sports clubs was equal to 5.2±0.8 l, FVC - 4.2±1.1 l. The VC and FVC indices were lower (р≤0.01) in the students not engaged in sports than in student-players; however, they corresponded to the guideline values. Proceeding from the in-depth study of VC, one of its components - inspiratory reserve volume (IRV), determining the extra lung expansion and ventilation capacity, equaled 2.2±0.2 l in basketball players, while in the case of untrained students it amounted to 1.7±0.3 l. Other indices, ERV and IRV, were also higher in students involved in sports.

MBC is indicative of the increase of reserve respiratory capacities, and in basketball players it was equal to 96.7±33.1 l vs. 84.6±16.8 l in non-athletes (р≤0.01) [3]. The pronounced efficiency of lung ventilation, increase of spare respiratory capacities owing to the enhancement of bronchial patency and force produced by the respiratory muscle contraction, increased functional capacities of the respiratory system are typical for representatives of team sports [6]. There were no significant differences between the bronchial patency indices (р≤0.05) in students attending basketball sports clubs and those from the control group.

While evaluating their external respiration, the indices of static and dynamic volume and lung capacity were significantly higher in students engaged in sports compared with those not doing sports. It makes sense, as the state of the respiratory system is known to depend on the motor activity of the body. Physical load has a training effect on the respiratory system [5].

All in all, the volume (static) parameters and volume-speed characteristics of the system of external respiration of student-basketball players and students not engaged in sports are either at the level of due values or exceed them, which testifies to the good functional state and big adaptive capacities and reserves of the respiratory system. It is important to have reasonably good functional capacities of the respiratory system to achieve high results in sport and perform well in view of the strict requirements for the state of the respiratory system due to the specifics of this sport (the need for rapid mobilization of the functions of external respiration caused by the constant need to shoot ahead during the game, short or long-distance).

A heightened effect of the HF-waves on the overall spectrum of the heart rate variability at rest in students playing basketball in sports clubs was detected, which proves the enhancement of the regulatory and adaptive capabilities, reduction of the cortical and subcortical influences on the cardiac function and activation of self-regulation processes, energy-saving functioning of the body. Those who are engaged in basketball sports clubs have higher static and volume-speed indices of the system of external respiration compared to student-non-athletes. The reserve capacities and endurance under the influence of regular sports loads (twofold on the average if compared with students not involved in sports) can be enhanced by increasing the indices of VC, MBC, TV, IRV, ERV, FVC.

Conclusions. The indices of the cardiorespiratory system of the students playing basketball in sports clubs are very efficient. The functional system formed under the influence of regular muscular activity ensures optimum adaptation to physical load [1]. In order to manage the adaptation process more efficiently, prevent adverse functional changes and protect health of students, it is necessary to get much closer to the solution of the problem of individual adaptation to the mass sport conditions. Both insufficient and excessive muscle loads beyond the regulatory and adaptive capabilities and dangerous for students' health can be avoided in practice of physical education only if knowing individual adaptive features and reserve capacity of the body at different stages of basketball training sessions.

The allocated peculiarities of adaptive responses of students can be used when elaborating well-grounded evaluation criteria for functional reserves of the body, criteria of control and optimization of training sessions, and can serve the basis for a differentiated approach to load standardization and make it possible to get closer to the development of the problem of individual adaptation.

References

1. Anokhin, P.K. Central issues of the theory of functional systems / P.K. Anokhin. – Мoscow: Nauka, 1980. – 200 P. (In Russian)
2. Baevsky, R.M. Problems of adaptation and health doctrine / R.M. Baevsky. –  Мoscow: Publ. h-se of RUPF, 2006. – 284 P. (In Russian)
3. Grechishkina, S.S. Integral analysis of the functional state of the cardiovascular system of students playing football in sports clubs / S.S. Grechishkina, M.N. Silant'ev, E.A. Ivantsov // Teoriya i praktika fizicheskoy kul'tury. – 2013. – № 8. – P. 56–61. (In Russian)
4. Petrova, T.G. The features of the neurophysiological status and aerobic capacity of athletes with different purposes of the training process / T.G. Petrova, T.V. Chelyshkova, N.N. Khasanova // Teoriya i praktika fizicheskoy kul'tury. – 2013. – № 8. – P. 17–22 (In Russian)
5. Chogovadze, A.V. Organs of external respiration / A.V. Chogovadze // In: Sports Medicine. – Мoscow: Meditsina, 1984. – P. 60–74. (In Russian)
6. Shakhanova, A.V. The influence of sports exercises on functional state and regulatory and adaptive capacities of young football players aged 10-15 years in view of their somatotypes / A.V. Shakhanova, A.A. Kuz'min // Teoriya i praktika fizicheskoy kul'tury. – 2013. – № 8. – P. 22–26. (In Russian)

Corresponding author: Kuz@maykop.ru