A.A. Povzun, associate professor, Ph.D.
V.D. Povzun, professor, Dr.Hab.
V.V. Apokin, associate professor, Ph.D.
O.A. Fyntyne, associate professor, Ph.D.
Surgut State University, KhMAR-Yugra, Surgut

Key words: biorhythm, chronobiological analysis, nonspecific adaptability, physical loads.

Adaptation as man’s adjustment to changing conditions of existence is a focal point of his life, because his health condition is largely determined by his adaptation reserves and especially his ability to activate them at a critical moment. In this context, the problem of adaptation of students in higher school is an important condition for successful pedagogical activity [1]. Managing students’ adaptation in higher school means to enhance resistance of a student’s body that can be specific and nonspecific and forms the ability to respond in an adequate way to a variety of effects. Sport and physical education are considered to be the most effective means of increasing nonspecific resistance.

The doctrine of man’s adaptation to physical loads is indeed one of the most important methodological foundations of the theory and practice of sport. However, such success is not the main goal for sports but is above all the means necessary to achieve sports results. So the answer to the question of whether improvement of sports skills and adaptation to physical loads contributes to maintaining health and high physical working capacity of students in different conditions of everyday life is not so straightforward as it seems [2, 3, 4, 5].

Undoubtedly, in such cases we are not talking about the harm of sport or physical loads but about the need to understand their role and the way these loads influence the nonspecific ability of the body that is not related to sports activities and about the evaluation of the possibility of thus increasing its reserve capacity. Thanks to understanding this, the necessary conditions can be created for the purposeful organization of health promotion in the course of both academic and nonacademic activities of a student and the types and limits of loads necessary and sufficient for getting optimal results can be determined [6, 8].

Homeostasis is both an objective criterion for such an assessment and a fundamental indicator that is equivalent to the concept of adaptation in terms of its level, while biological rhythm is the most accessible measure of the state of homeostasis that among other things can give an idea not only about the current state of adaptability of the body but also serve as a basis for a long-term forecast [7]. Seasonal revert to standard time or daylight saving can become an indirect and nonspecific factor that is unrelated to physical fitness and sports skills and at the same time provides simultaneous and equally intensive impact on the state of any body. Hence, the purpose of the present paper was to attempt to study the realignments of biorhythms of the major physiological parameters of the circulatory system common for students of the Faculty of Physical Culture during the revert to standard time and therefrom try to estimate their level of nonspecific adaptability.

Changes in the circadian organization of key physiological indicators occurred in male and female students of the Faculty of Physical Culture of SurSU of the same age group living in the city of Surgut. 46 people were involved in the experiment. The study was carried out in view of chronobiology 4 times a day: 8, 12, 16, 20 hours. Measurements were carried out for 3 days before the date of revert to standard time, in the day of time revert and during 3 days after the revert. The indices measured included: body temperature (t), heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure. The indices calculated based on the data were: pulse (PP) and average dynamic (ADP) pressure, systolic volume (SV) and cardiac output (CO). The obtained data were subject to standard mathematical processing. Biorhythmological criteria of nonspecific adaptability were calculated and evaluated, as indicated in the work of Moiseeva [7], by calculating the criterion for assessment of the degree of organization of the single day curve, criterion of degree of constancy of the curve structure (CC) and variability criterion (VC). Functional status by means of the criteria was assessed by determining three digits. In case of a good adaptation level the criterion of degree of organization (OC) ranged from 3.2 to 4.0, the criterion of degree of constancy (CC) - from 7/9 to 9/9, the variability criterion (VC) ranged from 3 to 5. The results of the calculations of changes of these criteria during the revert to standard time are shown in Table 1. It should be marked that the values of the variability criterion (VC) are indicated in percentage for the better follow-up of their changes during the zone time offset.

Table 1. Changes in the criteria of nonspecific adaptability of physiological indicators of students of the faculty of Physical Culture in consecutive measurements during the zone time offset.

Assessing the state of the rhythm of physiological indicators during the zone time offset, we showed that the time shift leads to changes in its organization and structure and, consequently, in the state of functional and adaptive capabilities of student’s body [8, 9]. However, the criteria of nonspecific adaptability serve as a measure of immediate adaptation that allows not only to evaluate the current state of adaptation capacity of the body, but also to become the basis for a long-term forecast, and characterizing their changes it should above all be noted that the level of variability criterion (VC) is relatively low both before and after the time offset. The lack of any regular changes of this indicator means that either the external influence was insignificant, or, more likely, indicate very weak attempts of the human body to intensify its adaptive capabilities, as the possibilities it has are simply not enough. Indeed, the key hemodynamic parameters (CO, PP, HR) were initially quite high, but after the zone time offset they only decreased. Very low values of all the other hemodynamic indicators make one think once again about the “physiological cost” of such a reaction.

This situation in the student community can be, on the one hand, a result of constant stress or fatigue, and on the other hand, serve as an indirect confirmation of the presence of at least inner desynchronosis. The high value of the HR variability criterion that probably determines the high value of this criterion for CO favours the first assumption. Such dependence is more typical for untrained people or indicates the state of fatigue.

This conclusion is also confirmed by the criteria that characterize the state of rhythm itself, for example, the criterion for assessment of the degree of organization of the single day curve (OC) that reflects the severity of the curve and consequently the synchronization of the rhythm with external factors and a clear alternation of activity in accordance with them. A decrease of OC seen in flattening or straightening the single day curve may indicate at least rhythm restructuring and its synchronization with the new external factors. According to the obtained result, this indicator does not change significantly, in our group even though it does not look ideal, and small shifts that take place can not serve as evidence of existence of external desynchronosis, that is one caused by the zone time offset. Low values of this criterion, however, especially for pressure indicators, suggest a low adaptive reserve of the body and a shift of hemodynamic load towards the heart, that again confirming the presence of fatigue. This situation is fully reflected by changes in the values of the last criterion - the degree of constancy of the curve structure (CC). This indicator describes the constancy of the rhythm structure, even if not very pronounced, i.e. a repeatable pattern of the single day curve during a certain period of time.  The decrease level of the rhythm recurrence is not high here, as is the level of its organization, but rather due to the fact that there is almost nothing to decrease. Only three indicators out of the eight measured are above satisfactory even before the zone time offset.

This situation is more typical for an untrained body, which itself suggests either that the influence of the external factor is more than significant, or that the body is in the state of fatigue and activates its capabilities by any means available in this state. Given all the findings, the second conclusion is much more likely, and therefore in our case it is at least questionable to speak about a high level of nonspecific adaptability of athletes. Moreover, we have every reason for thinking that athletes’ body is in a state of internal desynchronosis, and intense physical load is one of the possible reasons for it [8]. This means that the adaptation effect should be assessed not by the level of sports achievements or by the increase of individual physiological or even physical indicators. If a university organizes such a work, its assessment should be based on fundamental indicators reflecting the complex state of functional and adaptive capabilities of the body, and these indicators should be evaluated regularly and in the dynamics. One of these fundamental indicators is the structure of the biological rhythm; thanks to its analysis one can estimate not only the current state of adaptabilities of the body, and cannot be the basis for long-term forecasts.

References

1. Samarin, A.V.  The problem of adaptation and health of university students // International Journal ‘Nauka i mir”. – 2013 - №4 (4). – P. 274. (In Russian)
2. Povzun, A.A., Grigor’ev, V.A., Apokin, V.V., Efimov, Yu.S. Comparative analysis of seasonal changes in the body's adaptabilities of female skiers in terms of biorhythms // Teoriya i praktika fizicheskoy kultury. – 2010 – № 8. – P. 95-98. (In Russian)
3. Povzun, A.A., Losev, V.Yu, Apokin, V.V., Rabchenyuk, E.P. Comparative biorhythmological analysis of seasonal changes in adaptabilities of pupils actively involved in sports // Teoriya i praktika fizicheskoy kultury. – 2011 – № 2 – P. 83-85. (In Russian)
4. Povzun, A.A., Apokin, V.V., Pavlovskaya, V.S. Biorhythmological approach to arrangement of correctional work with mentally retarded schoolchildren by means of physical culture // Teoriya i praktika fizicheskoy kultury. – 2011 – № 6 – P. 90-92. (In Russian)
5. Pavlovskaya, V.S., Povzun, A.A., Rabchenyuk, E.P. Chronobiological characteristics of seasonal adaptation to physical load of pupil-athletes // Vestnik SurGU. Meditsina. – 2009 –- № 3. – P. 81-89. (In Russian)
6. Povzun, A.A., Povzun, V.D., Apokin, V.V. Biorhythmological assessment of the role of physical culture in organization of recreational work at university // Teoriya i praktika fizicheskoy kultury. – 2013 – № 2 – P. 85-88. (In Russian)
7. Moiseeva, N.I. Biorhythmological criteria of nonspecific adaptability / N.I. Moiseeva // Fiziologiya cheloveka. –1982. – V. 8, – №6, – P.1000-1005. (In Russian)
8. Apokin, V.V., Povzun, A.A., Vasil’eva, N.V. Change in adaptabilities of students of sports and non-sports departments within the revert to standard time // Teoriya i praktika fizicheskoy kultury. – 2012 – № 2 – P. 91-95. (In Russian)
9. Pavlovskaya, V.S., Povzun, A.A., Vakhlova, M.S., Samarskaya, E.O., Vasil’eva, N.V. Changes in the structure of biorhythms of basic physiological parameters in students of medical faculty during the revert to standard time. // Vestnik SurGU. Meditsina. – 2010 – № 6. – P. 4 – 15. (In Russian)

Corresponding author: apokin_vv@mail.ru