CC BY
105
DOI 10.14526/2070-4798-2019-14-1-176-184
Methodological approaches during scientific research works organization in the sphere of physical culture and sport
Evgeniy V. Bykov, Nadezhda P. Petrushkina, Olga I. Kolomiets, Nadezhda A.
Simonova
Scientific Research Institute of the Olympic Sport, Ural State University of Physical Culture Chelyabinsk, Russia ORCID: 0000-0002-8868-7489, bev@yandex.ru ORCID: 0000-0002-0830-0206, 25ppnn@mail.ru ORCID: 0000-0003-4623-856X, Kolomiec_o@mail.ru ORCID: 0000-0002-8441-9937, nadin@mail.ru
Abstract: The research work presents the main principles of scientific research work planning and organization in the sphere of physical culture and sport. The article considers the peculiarities of descriptive research organization in the sphere of sports physiology and medicine. Materials. We describe the principles of the studied athletes contingent formation, which correspond with the aims of the research. Research methods. By the example of own research works the authors substantiate the approaches to the indices selection, which are analyzed. The scientists underline the importance of monitoring research works using modern high-tech facilities (with the corresponding software support), which helps to register daily dynamics of an athlete's state. Formed in this case data bases (registers) are the base for multifactorial analysis, model characteristics of the studied phenomenon setting and its appearance prediction. Conclusion. Thus, we create an athlete's "portrait" (profile), on the basis of which individual program of an effective rehabilitation or health preservation is created.
Keywords: scientific research planning, prediction, medical-biological scientific research works, statistical methods, physical culture and sport.
For citation: Evgeniy V. Bykov, Nadezhda P. Petrushkina, Olga I. Kolomiets, Nadezhda A. Simonova. Methodological approaches during scientific research works organization in the sphere of physical culture and sport. The Russian Journal of Physical Education and Sport. 2019; 14(1): 151-157. DOI 10.14526/20704798-2019-14-1-176-184
Introduction Different aspects of the research works in
It is known that any research work planning physical culture and sport are divided into empirical is more important than the received results analysis. and experimental. The main difference between them An improper approach to research work planning is is the following: in the first case no interference is impossible to change then. At the same time, results accepted (training process correction, rehabilitation analysis can be held one more time or using another means use and etc.). In this case the information method for significant conclusion determination about the status of the respondent is received [7]. Planning a scientific research is the process, in the definite moment. In the second case this in terms of which experiment methodology and interference is realized and its effect is documented. statistical analysis are organized in a way to accept In this article we present the approaches to research or reject the main (null) hypothesis. At the same works planning and organization, held by us for the time, the conclusions should be valid. Thus, the components analysis, which characterize athletes' validity of the results mainly depends on the plan health state, their training level and peculiarities of of its realization. Any research planning and design rehabilitation.
provides the order of data gathering determination Descriptive research precedes any scientific
and the best way of its analysis. research planning. As a result we see how the
problem is studied and it helps to define the urgency and novelty of the planned work. Descriptive research works include the reviews concerning the prevalence rate of the definite phenomena, the series of cases, observations results study, gathered data analysis and etc..
Descriptive research work considers frequency, natural dynamics of the studied process development and determinants (main factors) of the definite state. At the same time, the main features or tendencies for the definite situation are determined, not the reasons for their presentation and the effects of influence on different elements of the studied phenomenon. For example, before setting the peculiarities of highly-qualifies athletes' rehabilitation it is important to "outline the terms", know the main functional systems. The work of them is directed toward this state achievement at different stages of training, while going in for different kinds of sport. It is also important to know the stages of rehabilitation, abilities of rehabilitation programs realization and athletes' health preservation and etc. Descriptive research work for disorders in puberty age hockey players' health state revelation helps to underline the main tendencies in teen-agers' health, differences with the groups of non-athletes and the factors. These factors provide teen-agers' health state disorders appearance, but not the effect of going in for sports itself.
Analytical research works usually (but not always) consider one or several specific hypotheses of athletes' definite states appearance (training level, fatigue, traumatism, rehabilitation and eta) and/or the effect of different interferences for their prevention or achievement. The received results can be also considered in descriptive (connotative) regimen. They can be also analyzed in order to check the hypotheses. It gives an analytical characteristic to these research works. Such kind of research works are planned in order to estimate not only the reasons, but also causal associations (which reveal cause-effect relations of phenomena and which prove some hypothesis or theory).
Then during research planning the main item, which should be considered is the principle of contingent formation. Contingent means a group of people, who will be under observation. As a rule, the
experimental group (or groups) is created, where specific influences will take place (the character of muscular loads, the peculiarities of the training process and rehabilitation and etc.). In order to estimate the effectiveness of such kind of influence the control group (or groups) is created. These experimental and control groups differ only in character of influence. According to other parameters they should be similar (sex, age, qualification). In our research of studying the peculiarities of highly-qualified athletes' rehabilitation we examined people, who go in for cyclic and acyclic kinds of sport [5, 16, 17]. The kind of sport became the difference between the groups. The comparison was held between the athletes with different training process orientation. According to other features groups of athletes had much in common. As they were formed according to "pair control" principle [2]. It means they were selected according to sex, age, sports qualification, experience and other parameters. "Pair control" principle helps to exclude different factors impact. It is able to change the results. It is obvious that during research work planning we should have information about such "interferring" factors.
In another research, connected with health state of puberty age hockey players, three groups were created: medians, accelerants and retardants. All they played in one team, had the same sports experience, had one trainer. The difference was only in the level of biological age correspondence with real age [30].
Another important item of research design is informative indices selection. They will be considered during the research realization. For rehabilitation peculiarities estimation among highly-qualified athletes we chose different characteristics of vegetative status. The vegetative status is an integral index of an athlete's state (both during sports activity fulfillment and at different stages of rehabilitation) [3, 6, 8, 11, 19,].
For athletes' vegetative status complex estimation we estimated traditional indices of heart rate (average, maximum, minimal value), hypoxia resistance (oxygen consumption indices - average and maximum value and post-training oxygen consumption), the degree of sympathetic and
cranial division prevalence [4, 6, 18,19 ].
As metabolism character and level also reflect the quality of rehabilitation, we analyzed the following indices: metabolic equivalent, maximum aerobic abilities and general energy exchange, including owing to carbohydrates and lipids [8, 20].
During health state study among puberty age hockey players we planned to state the factors, which condition young hockey players high level traumatism. As in the groups of accelerants and medians traumatism turned out to be higher, than in the group of retardants, in each defined group we studied the peculiarities of neurophysiological indices. These indices are responsible for sports activity effectiveness and for timely and correct reaction during the game. It can decrease the level of traumatism. Thus, we selected several functional tests [4, 29, 13, 17, 31, 21]. Simple visual-motor reaction characterizes the level of nervous system structures excitability. These structures determine the speed of reaction in the given game moment. Critical frequency of binocular flickers characterizes flexibility level of nervous system structures. They are responsible for the speed of transfer from one technical-tactical action to another. The time of reaction to a moving object reflects the level of excitability and inhibition processes stability in a nervous system and defined the accuracy of technical-tactical actions in the given game moment. Noise immunity and attention tests (Schulte-Platonov test) characterize corresponding qualities. In order to estimate working capacity, fatigue coefficient and the strategies of adaptation to physical load, which change the athlete's status, we used tapping test.
During scientific research works realization in the sphere of sports physiology and medicine a large complex of indices, registered at the same time period, is analyzed. In this connection an important demand concerning research planning becomes equipment choice. It is necessary to estimate the athlete's state in terms of "field" conditions. In these cases it is effective to use simple (available in fulfillment and estimation) methodologies.
Traditionally for metabolism estimation different biochemical and hormonal indices estimation are used. The difficulty of such kind of research works fulfillment is conditioned by
invasiveness, special equipment and expensive reagents use. These indices registration in the definite moments of time gives some uncertainty during the received results interpretation.
Nowadays scientists pay great attention to monitoring hardware ("noninvasive") research works. They help constantly (every second) register functional changes in the main systems of life support not only during training, but during late rehabilitation. For getting full information concerning the athlete's state it is necessary to have modern high-technology equipment.
On the basis of the twenty-four-hour observation results over highly-qualified athletes' health state we estimated the character of adaptation to the definite muscular activity. We revealed "weak points" of the athletes, predicted success of their activity and corrected timely the training process and rehabilitation program [16].
For rehabilitation estimation according to several physiological indices during the sleep (period since 10 p.m. till 6 a.m.) we held the athletes' state monitoring using Firstbeat-bodyguard measuring (Firstbeat-Technology-Ltd, Jyvaskyla, Finland). Stress and rehabilitation levels were determined with the help of R -R- intervals in real conditions during the sleep. Then the results were analyzed with the help of the software (version 5.3.0.4). This program helps to classify the received results. It takes into account individual peculiarities of different physiological indices: heart rate and vegetative control and estimate the quality (index) of rehabilitation on this base [15, 18,19, 25, 8].
Rehabilitation variables within 24 hours of monitoring were used for the time determination. It is necessary for complete organism rehabilitation. The research protocol [24, 15, 16] also provided special physical loads during morning and evening trainings and metabolic adaptive changes registration during 24 hours. The received results were analyzed with the help of the corresponding software
(version 5.3.0.4).
For the main characteristics of nervous process study among puberty age hockey players neurodiagnostic complex "Psikhotest" (Ivanovo, Russia) was used. This complex has a program
maintenance, which helps to get full information about each studied index. At the same time, we have not only quantitative (ms, MHz, c.u.), but also qualitative estimation of the latter (high, average, low level and etc.) [30].
In the distributive approaches monitoring results were estimated concerning intragroup and/or the athlete's individual indices changes by means of (Z-mark) transformation and (usually voluntarily) thresholds determination for trivial and significant changes (for example, Z-score >1) [1, 5]. In the first case the mark or an athlete's answer compared to the mark or answer in the control group [3] and the analysis depended on the activity level and heterogeneity of the group. During considerable changes we used distributive approach (intraspecific) "inside" an athlete. This approach usually estimates the observed values/ changes as significant ones, when they are out of "normal" fluctuation the average mean [1, 10]. Moreover, changes during the week can be expressed in a form of standardized differences, for example, a weekly change divided by a weekly standard deviation (SD) [7].
Then, as a rule, the first stage of biostatistical analysis is held [7, 12, 23]. After determining the character of the studied feature distribution we fulfill mean values and this feature variability calculation (in case of normal distribution-normalized asymmetry and excess coefficients calculation or symmetry diagram construction) or its ranging (in terms of non-standardized distribution). Validity estimation of quantitative indices differences (mean values) between the groups in the first case is held according to Student's test, in the second case according to Wilcoxon criterion (for the same volume samples comparison) or Mann Whitney U-test (in terms of random volumes samples). For qualitative characteristics comparison (distribution according to the level of marks- high, average, low and etc.) Fisher's ratio test is used [2, 12].
It should be noted, that program maintenance of a modern diagnostic equipment gives an opportunity for the bases of the initial data (registers) creation with the corresponding abilities of further voluntary groups formation, corresponding with the definite research objective [5,
22, 24]. Then these databases can be enlarged with the information, received during another equipment use and also during a dynamic observation over an athlete.
The latest item gains special importance for the analysis fulfillment. The analysis provides connection setting between the studied features, which in case of miltifactorial analysis are considered model characteristics of the studied phenomenon.
Different approaches to miltifactorial analysis and stage by stage procedure of its fulfillment are described in the research works [2, 28, 18, 27, 22].
During the first stage we used cluster analysis for the structure analysis of the indices range according to the absolute values of correlation coefficients between them. The program of calculations is based on single-coupling method. This method is based on a successive combination into clusters of similar features. It is known that two objects are identical, if describing them variables have the same values. Similarity between the pairs of variables was determined by the degree of connection between them. As the measure of connection we used the coefficients of an absolute correlation, which help to decrease the number of incorrect classifications.
We chose cluster analysis because analyzed by us features have unequal dimensionality [14, 27]. During the effectiveness of rehabilitation study among highly-qualifies athletes - time of sleep and wakefulness, heart rate and respiration frequency, the character of metabolic processes and others. During teenagers' health estimation - age, weight and height, results of neurophysiological test, different indices, the number of traumatism cases and etc. In terms of different measurement units (ms, kg, cm, MHz and etc.) before the search for minimal distances between the features during cluster analysis, we held variables rating in order to make the average be equal to zero and variance to one. By means of single-coupling method we considered the matrix of similarity and combined the most similar objects.
As a rule, during the first stage "events" are considered as independent clusters. During the last stage all events are combined into one big
equation we held gradually. During each stage we included the variable. It considerably improved dependent variable prediction and eliminated the variables. They don't improve prediction. The predicted part of "success" helped to calculate the possibility of the studied phenomenon appearance (full-rate rehabilitation of highly-qualified athlete or traumatism of a young hockey player) in terms of the existing set of the studied factors (independent variables). The received coefficients formed the base for prediction. As any prediction provides some uncertainty, for validity determination standard residual values are used [22, 11, 12]. Prediction is considered valid if standard residual values are within the following interval: from -3,0 till 3,0.
Conclusion
Thus, scientific research planning and organization in sports physiology and medicine provide stage by stage work. It includes descriptive research, correct formation of the athletes examined groups and information indices selection. It is necessary to underline the importance of monitoring studies using modern high-tech facilities (with the corresponding software support). They help to register daily dynamics of an athlete's state. Formed in this case data bases (registers) are the base for multifactorial analysis, model characteristics of the studied phenomenon setting and its appearance prediction. The athlete's "portrait" (profile) creation, on the basis of which we plan an individual program of an effective rehabilitation or health preservation, gains not only scientific but also practical significance.
group. The succession of the combined clusters is demonstrated in a form of shaded correlation matrix. It helps to see the connection coefficients of the studied phenomenon (fatigue, rehabilitation and traumatism) with the range of factors. They are revealed by us as model characteristics during the first stage of vegetative regulation study among highly-qualified athletes and/ or neurophysiological status of puberty age hockey players [18,19, 30, 31 9, 14, 13].
Modern level of scientific research works provides the studied state (phenomenon) prediction in terms of the existing range of factors. It is impossible without multivariate analysis [7, 22]. In this connection the objective of the final stage was in a special model creation. This model reflects mathematical ratio between the studied phenomenon (rehabilitation effectiveness among highly-qualified athletes and traumatism of teenagers) and the factors, which determine them (the peculiarities of vegetative regulation of the first and neurophysiological status of the second).
Initially we used logistic function. It shows studied indices exponential dependence (dependent variables-rehabilitation effectiveness of highly-qualified athletes or traumatism of young hockey players) on possible etiologic features (independent-predictive variables). They were in the past (an athlete's qualification, kind of sport, character of training) or in present (anthropometry results, the level of pubertal maturing, neurophysiological characteristics and etc.) [26, 31, 12, 9,18,19 ].
With the help of logistic regression from the set of features, earlier defined during cluster analysis, we defined the features or combinations of features. They were the most significant for prediction. For the possibility calculation of the studied event realization according to the received results we solved the equation. This equation included predicted part of "success" (possibility of full rehabilitation of a highly-qualifies athlete or traumatism of puberty age hockey player of the definite biological maturity level), regressive model coefficients. They were determined according to real results and also independent variables [7, 22, 11, 12]. Variables selection in logistic regression
References
1. Akenhead R., Nassis G. P. Training load and player monitoring in high-level football: current practice and perceptions. Int. J. Sports Physiol. Perform. 2016; 11: 587-593. DOI: 10.1123/ ijspp.2015-0331
2. Album A. Introduction to Modern Epidemiology. Second edition. Epidemiology Resources Inc. 1990: 122.
3. Aubert A.E., Seps Seps B., Beckers F. Heart Rate Variability in Athletes. Sports Medicine. 2003; 33(12): 889-919.
4. Bykov E.V. Various indices of schoolchildren's health status in a big city depending on their life style. Fiziologiya cheloveka= Human physiology. 2001; 27(1): 142-144 (in Russ., in Engl.).
5. Bykov E.V., Kolomiets O.I. Modern information technologies to improve training process control methods. Teoriya i Praktika Fizicheskoy Kultury = Theory and practice of physical culture. 2016; 5: 59-61. DOI: 2-s2.0-84978091889 (in Russ., in Engl.)
6. Christoph Schneider, F. Hanakam, T. Wiewelhove, A. Doweling, M. Kellmann, T. Meyer, M. Pfeiffer, A. Ferrauti. Heart Rate Monitoring in Team Sports—A Conceptual Framework for Contextualizing Heart Rate Measures for Training and Recovery Prescription. Front Physiol. 2018; 9: 639. DOI:10.3389/fphys.2018.00639 PMCID:
PMC5990631, PMID: 29904351.
7. Campbell M.J., Machin D. 3rd ed. Chichester: Wiley. Medical Statistics: A common-sense approach. 1999.
8. Isaev A.P. Bykov E.V., Adaptation to teaching loads in new educational institutions. Fiziologiya cheloveka= Human physiology. 2001; 27(5): 76-81 (in Russ., in Engl.)
9. Kolomiets O.I. Functional, mental and emotional balancing effects of synchronized and personified music of University athletes. Teoriya i Praktika Fizicheskoy Kultury = Theory and practice of physical culture. 2016; 5: 53-55. DOI: 2-s2.0-
84978069250.
10. McGuigan M. Monitoring Training and Performance in Athletics. Champaign, IL: Human Kinetics. 2017.
11. Stanley J., D'Auria S., Buchheit M. Cardiac parasympathetic activity and race performance. An elite triathlete case study. Int. J. Sports Physiol. Perform. 2015; 10: 528-534. DOI: 10.1123/ijspp.2014-0196
12. Ayvazyan S.A., Enukov I.S., Meshalkin L.D. Applied statistics. The basis of modeling and initial data handling. Finansy I statistika. 1983; 286.
13. Bykov E.V., Ryazantsev A.V., Chipyshev A.V., Mekeshkin E.A., Kazakova O.V. Psihofiziologicheskie I fiziologicheskie aspekty adaptacii k umstvennym nagruzkam uchachihsya mladshih klassov [Psychophysiological and physiological aspects of adaptation to mental loads of junior schoolchildren]. Russian Federation Ministry of education. South-Ural State University.
2010; 158.
14. Bykov E.V., Zinurova N.G., Chipyshev A.V., Kolomiets O.I., Lekontsev E.V. Postroenie tranirovochnogo processa na osnove sovershenstvovaniya metodov kontrolya funkcional'nogo sostoyaniya I ucheta geneticheskih faktorov [Training process organization on the basis of developing control methods of the functional state and genetic factors taking into consideration]. 2018; 130.
15. Bykov E.V., Kolomiets O.I. The methods of control improvement over the training process on the basis of modern information technologies (Firstbeat). Teoriya i Praktika Fizicheskoy Kultury = Theory and practice of physical culture. 2016; 5: 59-61 (in Russ., in Engl.).
16. Kolomiets O.I., Bykov E.V., Petrushkina N.P. Synchronized musical impact as rehabilitation means of athletes (martial arts). Pedagogiko-psikhologicheskie i medico-biologicheskie problem fizicheskoy kultury i sporta = Pedagogico-psychological and medico-biological problems of physical culture and sport. 2017; 12(1): 167-174. DOI: 10.14526/01_2017_175 (in Russ., in Engl.)
17. Kolomiets O.I., Bykov E.V., Chipyshev A.V. Modern technologies of sport and physical activity medical-biological maintenance. Naucho-Sportivnyi Vestnik Urala i Sibiri. 2017; 2(14): 24-29 (in Russ.).
18. Kolomiets O.I., Orekhov E.F., Bykov E.V. Mechanisms of heart contractile function regulation among athletes of different kinds of sport. Uchenye zapiski universiteta im. P.F. Lesgafta. 2014; 12(118): 103-109 (in Russ.).
19. Kolomiets O.I., Bykov E.V. Heart rhythm variability during adaptation to physical loads of different orientation. Uchenye zapiski universiteta im. P.F. Lesgafta. 2014; 12(118): 98-103 (in Russ.).
20. Kolomiets O.I., Petrushkina N.P., Bykov E.P. The peculiarities of metabolic adaptive changes during different physical loads. Nauka. Innovatsii. Tekhnologii. 2017; 1: 207-216 (in Russ.).
21. Kolomiets O.I., Petrushkina N.P., Bykov E.P., Yakubovskaya I.A. Functional state peculiarities of central nervous system among athletes with different training process orientation. Pedagogiko-psikhologicheskie i medico-biologicheskie problem fizicheskoy kultury i sporta = Pedagogico-psychological and medico-biological problems of physical culture and sport. 2017; 12 (2): 217-225. DOI: 14526/01_2017_225 (in Russ., in Engl.)
22. Koshurnikova N.A., Petrushkina N.P., Kabirova N.R., Okatenko P.V., Khokhryakov V.V. Rational risk estimation for population, living close to nuclear industry enterprise. Methodical approaches to rational risk estimation. The content of children register. Voprosy radiacionnoj bezopasnosti. 1996; 2: 46-50 (in Russ.).
23. Kochetov A.G., Lyang O.V., Masenko V.P., Zhirov I.V., Nakonechnikov S.N., Tereshchenko S.N. Metody obrabotki statisticheskih dannyh: metodicheskie rekomendacii dlya ordinatorov I aspirantov medicinskih uchebnyh zavedenij, nauchnyh rabotnikov [Methods of medical data statistical handling: methodical recommendations for attending physicians and postgraduates of medical educational establishments, researches]. RKNPK. 2012; 42.
24. Nikitin I., Kolomiets O.I., Bykov E.V. Rehabilitation analysis of highly-qualified athletes, based on heart rate variability: the method review of rehabilitation analysis. Problemy fizkulturnogo obrazovaniya: soderzhanie, napravlennost, metodika, organizatsiya: materialy IV-ogo Mezhdunarodnogo kongressa. 2015; 1: 646652 (in Russ.).
25. Oreshkina I.N., Kolomiets E.V., Bykov E.V. Heart rate variability monitoring of qualified skaters with the help of firstbeat methodology. Sovremennye metody organizacii trenirovochnogo processa, ocenki funkcional'nogo sostoyaniya I vosstanovleniya sportsmenov: materiay Vserossijskoj nauchno-prakticheskoj konferencii [Modern methods of the training process organization, functional state and athletes'
rehabilitation estimation: materials of All-Russian
Submitted: 16.12.2018
scientific-practical conference]. 2017; 190-193.
26. Petrushkina N.P., Kolomiets O.I., Simonova N.A. Morphofunctional status of puberty age athletes influence on sports injuries appearance. Teoriya i Praktika Fizicheskoy Kultury = Theory and practice of physical culture. 2016; 5: 38-40 (in Russ., in Engl.).
27. Petrushkina N.P., Zhukovskaya E.V., Kolomiets O.I., Karelin A.F. Fizicheskaya podgotovka k sluzhbe v Vooruzhennyh silah podrostkov s vysokim riskom razvitiya disadaptacionnyh narushenij [Physical training for service in the Armed Forces of teenagers with high risk of dysadaptation disorders development]. ID "Akademiya estestvoznaniya". 2017; 154.
28. Petrushkina N.P. Health of descendants (the 1st -2nd generations) of the first nuclear industry enterprise workers- industrial association "Mayak". Candidate's thesis. 2003.
29. Ryazantsev A.V., Bykov E.V., Chipyshev A.V. Neurovegetative and neurodynamic criteria of adaptation estimation among young chess players to mental loads. Teoriya i Praktika Fizicheskoy Kultury = Theory and practice of physical culture. 2014; 4: 7-10 (in Russ., in Engl.).
30. Simonova N. A., Orekhov E.F., Petrushkina N.P., Kolomiets O.I. The peculiarities of nervous system functional state and sickness rate of puberty age hockey players of different biological maturity level. Uchenye Zapiski universiteta im. P.F. Lesgafta. 2016; 3(133): 217-223 (in Russ.).
31. Simonova N. A., Petrushkina N.P. Peculiarities of sickness rate among puberty age hockey players. Vestnik Uralskoi meditsinskoy akademicheskoy nauki. 2014; 3: 175-176 (in Russ.).
Author's information:
Evgeniy V.Bykov - Doctor of Medicine, Professor, Scientific Research Institute of the Olympic Sport, Ural State University of Physical Culture, 454091, Russia, Chelyabinsk, Ordzhonikidze str., House 1, e-mail: bev@yandex.ru
Nadezhda P. Petrushkina - Doctor of Medicine, Senior Research Assistant, Scientific Research Institute of the Olympic Sport, Ural State University of Physical Culture, 454091, Russia, Chelyabinsk, Ordzhonikidze str., House 1, e-maib25ppnn@mail.ru
Olga I. Kolomiets - Candidate of Biological Sciences, Associate Professor, Scientific Research Institute of the Olympic Sport, Ural State University of Physical Culture, 454091, Russia, Chelyabinsk, Ordzhonikidze str., House 1, e-mail: Kolomiec_o@mail.ru
Nadezhda A. Simonova - Junior Research Assistant, Scientific Research Institute of the Olympic Sport, Ural State University of Physical Culture, 454091, Russia, Chelyabinsk, Ordzhonikidze str., House 1, e-mail:nadin@mail.ru
