A.V. Kabachkova, Ph.D.
L.V. Kapilevich, professor, Dr.Med.          
Tomsk State University, Tomsk, Russia

Key words: heart rate variability, overall fitness, frequency analysis.

Relevance of research. The problem of preservation and promotion of students’ health is complex and multifaceted. The current socio-economic situation prevents from creating favorable conditions for leading healthy way of life [5]. Moreover, many authors note the increase of incidence among students [4].

Students’ activity within classes is associated with increased body load, leading to wasting of the functional reserve, resulting in changes in the course of metabolic processes, failures in the interaction of many body functional systems, decrease of physical working capacity and development of fatigue. The arising stress in some cases leads to the development of physical and mental disorders. In his work "Students’ Health" N.A. Agadzhanyan [1] notes that over the years of university studies the number of healthy students decreases by 25.9%, and of the ones with chronic diseases increases by 20%. Thus, while studying at the university one-fifth of students changes from the category of relatively healthy to the category of chronically ill [1]. These students poorly adapt to studies that require learning large amount of information within limited time, hypokinesia, malnutrition and conflict situations, which, in the end, is followed first by the stress of their regulatory and compensatory mechanisms, and then pathological changes in functional systems. This requires a new approach to the development of science-based prevention activities.

Body’s adaptive activity to a variety of factors for various age groups is being studied at the moment. And it is important to organize monitoring, i.e. dynamic observation and analysis of obtained results but not just a single assessment of indices.

The purpose of the study was to estimate the results of monitoring of the functional status of undergraduates of Tomsk State University.

Materials and methods. Students’ physical fitness is annually monitored at the physical education department of Tomsk State University. The sports educational process on the department is organized using the personality-centered forms of physical education. Groups in the areas and types of motor activity are formed on the basis of criteria such as the peculiarities of personal motivation (student’s wishes), health and physical development. Since 2007 the department has expanded the monitoring program and included the psychophysiological testing, assessment of physical development, functional status and academic performance (Fig.).

Figure. Organizational chart of monitoring of students' individual adaptation to the educational and sports activities

Young men aged 17-19 years of the basic medical group were observed (n = 467). The study groups of students of two variants of sports technologies (football, karate) and conditioning technology (C) were examined. Doctor’s conclusion, students’ wishes and results of the competitive qualification were the compulsory conditions for the formation of sports groups. The conditioning study groups were made of students who failed at qualification for sports specializations, or those who had the primary motive of getting credit in physical education. Furthermore, the presence of informed consent was an additional inclusion criterion. Exclusion criteria were the disparity in age, the presence of sports category (1-3 adult, candidate master, master of sport), the lack of informed consent.

Results and discussion. In the process of physical education with the use of sports technologies body functional status of first-year students is presented in two varieties: "adaptive state" (73%) and "state of functional stress" (27%). Adaptive state is characterized by the well-balanced activity of the sympathetic and parasympathetic nervous systems and decrease of centralization of the mechanisms of vegetative regulation of heart rate. The state of functional stress is characterized by the noted intensification of sympathetic effects and centralized mechanisms of vegetative regulation of heart rate.

The analysis of the results of monitoring of students’ functional status of the body and physical fitness revealed the dynamics and the relationship between performance in study groups. Most students from the study groups (conditioning, football, karate) have an optimum functional status and physical fitness. However, there are students with the status of functional tension and low physical fitness. Such differences served the basis for the formation of subgroups in view of the dynamics of functional status during the first year of studies.

When studying adaptabilities Gevorgyan E.S. et al [3] revealed that daily mental load has a multidirectional effect on hemodynamic indices and regulatory mechanisms of heart rate control. There are three basic types of compensatory-adaptive reactions: adaptive type, state of functional tension, compensatory type. Each type of reaction is characterized by the activity of the sympathetic and parasympathetic autonomic nervous system (ANS), the degree of tension of regulatory mechanisms and the level of functional reserves. Adaptive reaction type corresponds to the physiological norm, the status of functional tension and compensatory type – to prenosological state that under adverse conditions can change to poor adaptation and failure in adaptation. The type of compensatory-adaptive reactions was determined using the diagnostic model of recognition of functional status of the body based on the results of cardiointervalography at all phases of the observation [2].

It was found that 73% (341/467) of first-year students have the adaptive type and 27% (126/467) – the state of functional tension. The students with compensatory type of reactions were not detected. Thus, the first subgroup included students with the adaptive type, the second – with the state of functional tension (Tab. 1).

Table 1. Characteristics of heart rate of the background test of first-year students with different types of compensatory-adaptive reactions

² – a statistically significant difference (p<0.05) between the indices 1 and 2 subgroups at the end of the year.

Adaptive type of compensatory-adaptive reactions is characterized by the balanced activity of the sympathetic and parasympathetic ANS. The values of the indices of mode (Mo) and amplitude of mode (AMo) are within the normal range, and their decline was marked by the end of the first year. The centralization of heart rate control has not been marked. The parasympathetic ANS activity increases. In the state of functional tension an increase in activity of the sympathetic ANS is marked. Tension index (TI) is within the normal range, but close to the upper limit.

The transition from the physiological norm to pathological states goes through a series of phases (prenosological state), in which the body tries to adapt to new environmental conditions for it by changing the level of functioning of various organs and systems. A certain degree of tension of regulatory mechanisms intended to mobilize functional reserves is required to preserve the current level of functioning in the new conditions or to adjust to a more appropriate level. Lower functional reserves promote higher degree of tension. That degree of tension of regulatory systems necessary to maintain homeostasis determines the current functional status. The initial level of functioning (vegetative tonus) represents the background activity of structures responsible for the regulation of the functional status of the body during adaptive activity. People with different vegetative tonuses have different body adaptabilities. In order of descending adaptabilities types of vegetative tonus are as follows: eutonia (normal tone of ANS), vagotonia (predominance of parasympathetic tone of ANS), sympathicotonia (predominance of sympathetic tone ANS), hypersympathicotonia (excessive sympathetic tone of ANS).

The degree of tension of regulatory mechanisms was assessed using spectral characteristics of heart rate: VLF, LF, HF. Several types of tension of systems of autonomic regulation of heart rate were identified on the basis of the ratios of spectral components. In the 1st subgroup the normal state of regulatory systems was marked in 87% (297/341) and regulation with the increased influence of the parasympathetic ANS in 13% (44/341) at the beginning of the year. At the end of the first year of studies this ratio changed slightly – 89% (303/341) of students with normal state of regulatory systems.  The states of tension of regulatory systems were marked in the 2nd subgroup (Tab. 2).

Table 2 Types of tension of heart rate regulation systems in first-year students from the 2^nd subgroup

The body's ability to adapt to new conditions or its adaptabilities depend on the supply of its functional reserves, on its ability to mobilize them in time and thus prevent the depletion of regulatory mechanisms. Functional reserve of the cardiovascular system and the body as a whole were assessed in accordance with the dynamics of the cardiointervalographic parameters during the orthostatic test. In the analysis of orthostasis several phases are identified based on the determination of the first changes and links of the mechanism of compensatory reactions when changing to a vertical position. The studies have proved the parasympathetic nature of the initial changes in heart rate (HR) and increase in the sympathetic activity during the development of changes in vascular bed and systems of autonomic regulation to the orthostatic test. The chronotropic heart response is not the main mechanism for maintaining cardiac output during orthostasis, its effectiveness depends on the response of the vasomotor center. In the 1st subgroup at the beginning of the year sufficient and excessive vegetative maintenance of activity was marked (45% (154/341) and 55% (187/341), respectively). In the 2nd subgroup - insufficient and excessive vegetative maintenance of activity (67% (84/126) and 33% (42/126), respectively). In the diagnosis of vegetative maintenance the original vegetative tonus was taken into account: the higher the initial level, the smaller the response to the exposure ("the baseline law").  The overcollateralization is characterized by the insufficient or reduced heart rate increase in orthostasis, and increased or excessive increment in case of insufficient maintenance. In case of inadequate growth of HR an increased or excessive consumption of functional reserves is marked.

Thus, the 1^st subgroup is characterized by sufficient functionalities of the body or the state of the minimum tension at optimal functioning of regulatory systems. In the 2nd subgroup there is an increased consumption or reduced functional reserves of the body, slight or moderate tension of adaptation mechanisms.

The level of overall physical fitness of students of the 1st subgroup at the end of the first year is mainly average or above the average. The positive dynamics (p<0,05) of test results of physical characteristics such as speed, flexibility, power and speed-strength qualities is marked. The level of overall physical fitness of students of the 2nd subgroup at the end of the first year is mostly average and below the average. The negative trend (p<0,05) of test results of such physical characteristics as speed and endurance is noted. At the end of the first year the academic performance was significantly higher in the second subgroup, in the second year – in the first subgroup.

Thus, each subgroup is characterized by its orientation of the adaptation process and the dynamics of indices of the functional status of the body during the first year. The nature of adaptation of students in physical education is determined by the initial functional status. Type of compensatory-adaptive reactions determines the efficiency of formation of the basic physical characteristics during the first year.

Conclusions. Students with adaptive compensatory-adaptive reactions have a positive dynamics in their test results of such physical characteristics as speed, flexibility, strength and speed-strength qualities, the average or above average conditioning level. A statistically significant increase in the academic performance is marked in the second year of studies.

In the subgroup of students with the state of functional tension the negative trend is observed in the test results of the physical characteristics of speed and endurance. The conditioning level at the end of the first year is mainly average and below average.

The indices of functional status that characterize the type of compensatory-adaptive reactions are related to efficiency of formation of physical qualities of students of the department of physical education and sport with the use of sports technologies: balanced regulatory effects of the sympathetic and parasympathetic autpnpmic nervous systems and reduced centralization of the mechanisms of vegetative regulation of heart rate are accompanied by the increase of the level of conditioning and special physical fitness.

References

1. Agadzhanyan, N.A. Students’ health / N.A. Agadzhanyan, V.P. Degtyarev, E.I. Rusanova et al. – Moscow, 1997. – 199 P. (In Russian)
2. Galeev, A.R. The model of identification of functional status of 6-17-year-old children’s body / A.R. Galeev, L.N. Igisheva// Vestnik novykh meditsinskikh tekhnologiy. – 2005. – V. 12. – № 1. – P. 30–33. (In Russian)
3. The dynamics of integral characteristics of heart rate variability and psychophysiological characteristics of students in case of one-day and -week educational loading / E.S. Gevorkyan, S.M. Minasyan, Ts.I. Adamyan et al. // Fiziologiya cheloveka. – 2006. – V. 32. – № 4. – P. 57–63. (In Russian)
4. Monitoring of students’ functional status using sports centered forms of physical education / L.V. Kapilevich, A.V. Kabachkova, V.S. Smirnov et al. // Teoriya i praktika fizicheskoy kultury. – 2008. – № 10. – P. 29–31. (In Russian)
5. Tsaturyan, L.D. Students’ health level nowadays / L.D. Tsaturyan, D.A. Androsova // Vestnik Stavropol’skogo gosudarstvennogo universiteta. – 2011. – № 74. – P. 63–69. (In Russian)

Author’s contacts: kapil@yandex.ru