Dr. Biol., Associate Professor A.A. Govorukhina¹
K.A. Mushtai¹
S.V. Kolomiets¹
Dr. Med., Associate Professor O.A. Malkov^1
1Surgut State Pedagogical University, Surgut

Keywords: students, heart rate variability, body component composition, sportization.

Background. The importance of formation and maintenance of students’ health, especially in the regions with harsh climatic and geographical conditions, is beyond doubt, as the body has to adapt to both aggregate natural factors and mental and other types of loads [3]. In this view, it is quite a challenge to choose the most rational ways to organize the students’ physical activity. Sportization is one of the ways [6], which is based on the independent choice of the type of physical load.

The body’s functional resource management during the adaptation to sports-specific muscular activity is carried out through the central and autonomous nervous, endocrine and humoral mechanisms, with their derivatives being the frequency ranges of heart rate variability [1]. However, vegetative dysregulation can be considered as an early sign of disadaptation to physical loads [2, 5, 7]. There is mixed evidence in the literature on the relationship between the heart rate variability rates and individual body component composition [4].

Objective of the study was to assess the state of the regulatory mechanisms and body composition indicators of the female students trained under the sportization programs.

Methods and structure of the study.  Sampled for the study were 118 female students of non-sports faculties of Surgut State Pedagogical University. During the 2nd year of study, the female students were trained under the standard physical education program, and the sportization programs were introduced in the 3rd year only. As a result of sportization of physical education, all the female students were divided into 3 groups depending on the selected training course: Group 1 – body conditioning with the elements of track and field athletics (n=40); Group 2 – volleyball (n=40), Group 3 – artistic gymnastics (n=38). Each female student gave a written informed consent for the study. At the time of the study, all the girls were in good health and had no complaints about their health for the previous two weeks.

The subjects’ heart rate variability was studied using the "VNS-Spectrum" hardware and software complex [8]. The following indices were analyzed: standard deviation of Normal-Normal (SDNN), root mean square of standard deviation (RMSSD), spectrum total power (TP), power of very low frequency waves (VLF), power of low frequency waves (LF), power of high frequency waves (HF), index of centralization (IC), index of activation of the subcortical centers (IASC). The fat body mass and biological age were determined using the "Tanita BC-730" analyzer.

Results and discussion. The dynamics of changes in the heart rate variability rates in the female students trained under various sports programs during the year are shown in Table 1. The median values of SDNN, reflecting the cumulative effect of the vegetative regulation before the introduction of the sportization programs, were found to be within the normal limits (40-80 ms) in Group 3 (artistic gymnastics) only. In the other two groups, this indicator exceeded the standard values and declined significantly after one year of body conditioning and volleyball practices.

Table 1. Indicators of temporary analysis of female students depending on type of physical load, Md (Q1-Q3)

Note. Hereinafter: p₁ – the significance of differences between the body conditioning groups before and after the introduction of the sportization program; p₂ – the significance of differences between the volleyball groups before and after the introduction of the sportization program; p₃ – the significance of differences between the body building groups before and after the introduction of the sportization program.

In other study groups, this indicator slightly exceeded the normal level in the 2nd-year female students, which indicated the relative predominance of the parasympathetic regulation unit. In the 3rd year of study, SDNN in the girls engaged in volleyball decreased statistically significantly (p=0.000), which may indicate a decrease in the autonomous regulation circuit activity and activation of the higher levels of regulation.

The analysis of RMSSD in all the study groups showed that this indicator exceeded the normal level (20-50 ms), thus testifying to a high level of activity of the autonomous regulation circuit. At the same time, the influence of the parasympathetic nervous system increased in the 3rd year of study as compared to the previous year (p=0.003). In other study groups, there were minor changes in RMSSD.

The female students engaged in volleyball were found to have a significant increase in the spectrum total power (p=0.019) due to an increase in the power of low (p=0.000) and very low frequency (p=0.015) waves, which indicated an improvement in the adaptive capacity of the cardiovascular system and stress tolerance (Table 2) after one year of training under the selected sportization program. The girls engaged in body conditioning practices demonstrated a statistically significant increase in high frequency values (p=0.043), which testified to a shift in the vegetative balance towards the predominance of the parasympathetic unit and increased vagal effects.

Table 2. Spectral indices of heart rate variability in female students depending on  type of physical load, Md (Q1-Q3)

The analysis of index of centralization and index of activation of subcortical centers during the year revealed statistically significant changes (p=0.039 and p=0.000, respectively) only in the group of girls engaged in volleyball, which indicated minimization of the effects of the central regulation circuit on the heart rate and a decrease in the subcortical center activity.

The dynamics of changes in the body component composition that correlated with the heart rate variability rates in the female students trained under different sportization programs during the year is presented in Table 3.

Table 3. Individual body component composition indices in female students depending on type of physical load, Md (Q₁-Q₃)

We found a correlation between the heart rate variability and body component composition parameters of the female students with different sports specializations. For example, before the introduction of the sportization program, in the female students trained under the body conditioning program with the elements of track and field athletics, the total power, VLF, and LF rates had a low positive correlation with the biological age (0.3-0.5). In the female students of Group 3, the biological age correlated with the total power, LF, and index of activation of subcortical centers rates (0.3-0.5), while the body fat percentage correlated with SDNN and RMSSD (0.3-0.5). In Group 2, the correlation relationships were detected only after the introduction of the sportization program: RMSSD and HF negatively correlated with the body fat mass (-0.3 - 0.5), while index of centralization - positively (0.321).

Conclusion. The introduction of the sportization program in the form of body conditioning with the elements of track and field athletics was accompanied by an increase in the activity of the parasympathetic regulation unit, a decrease in the body fat mass, and a decrease in the biological age. The volleyball practices during the year helped increase the adaptive capacity of the female students, reducing the activity of the parasympathetic nervous system, which before the introduction of the sportization program was somewhat above normal. Regular body building practices during the year contributed to the reduction of body fat percentage without causing any significant changes in the parameters of heart rate variability.

References

1. Wein A.M. Vegetative disorders. Moscow: Nauka publ., 2003. 408 p.
2. Drobyshev V.A., Guvakova I.V. Features of autonomic dysfunction in track athletes and methods of prevention. Proc. VI national scientific  forum «ReaSpoMed 2006». Moscow, 2006. pp. 38-40.
3. Zhuravleva I.V. [ed.] Student health: sociological analysis. M.: Institute of Sociology Russian Academy of Science publ., 2012. P. 252.
4. Karpenko Yu.D., Dmitriev D.A. Effect of body mass index on heart rate variability in students under relative rest and examination stress. Journal of Siberian Medical Sciences. 2012. No. 6. P. 21.
5. Kolomiets O.I., Bykov E.V. Heart rate variability during adaptation to various types physical activity. Uchenye zapiski. 2014. No. 12 (118). pp. 98-103.
6. Lubysheva L.I., Zagrevskaya A.I., Peredelskiy A.A. et al. Sportization in physical education system: from scientific idea to innovative practice. Moscow: Teoriya i praktika fizicheskoy kultury i sporta publ.. 2017. 200 p.
7. Taminova I.F. Role of orientation and intensity of training process in development of myocardial dystrophy of physical overstrain in athletes. Proceedings of the VI national scientific  forum «ReaSpoMed 2006». Moscow, 2006. pp. 148-150.
8. Shlyik N.I., Sapozhnikova E.N. Analysis of heart rate variability and ECG dispersion mapping in subjects in Mars-500parallel studies with different predominant types of autonomic regulation (Izhevsk experimental group). Vestnik Udmurtskogo universiteta. Ser. «Biologiya. Nauki o Zemle». 2012. No. 1. pp. 109-113.

Corresponding author: kris4450@mail.ru

Objective of the study was to assess the state of the regulatory mechanisms and body composition indicators of the female students trained under the sportization programs.

Methods and structure of the study. The article presents the results of study of the autonomic regulation mechanisms and body component composition of 118 female students of non-sports faculties of the Surgut State Pedagogical University, who were trained under the selected sportization programs during the year: body conditioning course with the elements of track and field athletics, volleyball, and artistic gymnastics. The subjects’ heart rate variability was studied using the "VNS-Spectrum" hardware and software complex. The body component composition was studied using the "Tanita BC-730" analyzer. The statistical data processing was made using the STATISTICA 10.0 software package.

Results and conclusions. It was found that trainings under one of the sportization programs during the year affected the subjects’ body composition and vegetative regulation indices. In the group of female students who had chosen the body conditioning course with the elements of track and field athletics, there was observed an increase in the spectrum power of the high frequency component of the heart rate variability, a decrease in the body fat percentage, and a reduction of the biological age. In the female students engaged in volleyball, the total spectrum power increased at the cost of increased spectrum power of the low- and very low frequency components, a decrease in the indices of centralization and activation of subcortical centers. Those involved in the artistic gymnastics did not have any significant changes in the heart rate variability indices, but were found to a reduction of the body fat mass. It was found that trainings under the sportization programs during the year had different effects on the parameters of the autonomic nervous system.