Dr.Hab., Professor A.P. Skorodumova¹
PhD A.A. Trukhachev^2
1Russian Federal Research Center for Physical Culture and Sports (VNIIFK), Moscow
²National Nuclear Research University "MEPhI", Moscow

Keywords: physical and functional fitness, factor structure, competitive success, elite tennis players.

Introduction. It is endurance types, speed and speed-strength qualities that play the key role in the competitive activity of elite tennis players.

The general direction of physical training of elite tennis players largely depends on the athletic qualities that the coach considers leading and prevailing, based on his own experience and intuition.

Identification of the leading physical qualities and factors that determine such qualities, the dependence of successful competitive activity on these qualities will enable to develop methodological recommendations regarding the training means and methods to be used, as well as make adjustments to the structural components of the training process.

Objective of the study was to analyze the key aspects of the physical and functional fitness factors in the national tennis elite.

Methods and structure of the study. The 17-23 year-old (n=36) elite tennis players were sampled for the study. Their speed, speed-strength and coordination abilities, flexibility and endurance types were assessed based on the results of the pedagogical tests. The athletes’ aerobic capacity was tested in the step load test "to failure" performed on a treadmill (running); anaerobic alactic capacity – in the 10sec cycle ergometer submaximal test. The tests helped identify 35 indicators. The tennis players’ competitive success was evaluated based on the points earned during the tennis tournaments. The tournament points form the basis of ranking in tennis.

Results and discussion. The data obtained were processed using a factorial analysis, owing to which the entire set of indicators could be described by a smaller amount of other parameters, called factors. A factor is a hypothetical hidden variable that combines several formally measured characteristics of an object [1]. As a result, fewer indicators incorporate into a single factor, which enables to describe the study object in a more compact manner. To identify the factors and, as a consequence, the factor structure, it is most justified to use the principal component method [2]. A significant peculiarity of this method is the possibility to go with the most informative components and exclude from the analysis the remainder. There are several criteria for determining the number of factors to be considered. In our case, the process was carried out in two stages: at the first stage, we kept only the factors with eigen values, equal to or greater than 1 (eigenvalue criterion). There were nine such factors. At the second stage, the number of factors was limited to the reproducible dispersion. The 75% border enabled to single out five most significant factors, which were thoroughly analyzed. These five factors accounted for 75% of the total sample variance (see Table 1).

Table 1. Structure of physical fitness of elite tennis players

^* – indicators being closely correlated with the competitive success rate.

Factor I combined five indicators of the athletes’ physical qualities. In the scientific and methodological literature and actual practice, aerobic capacity is associated with general endurance. The aerobic working capacity criteria closely correlate with the competitive success rates, which is understandable, as a tennis match, during which the athletes perform up to 100 short high-intensity jerks, lasts from 1.5 to 3.5 hours or longer.

The main forms of the speed abilities in tennis facilitate the execution of the majority of shots:

- a complex response rate - to determine where the ball sails, choose a counteraction and start its execution;

– a single movement – set a racket, make a step;

– acceleration speed, when one needs to return the ball having covered the 3-18m distance.

The speed of a single movement and acceleration speed closely correlate with the competitive success rate.

Abrupt movements or acceleration, especially performed with a change in the direction, are based on the athletes’ speed-strength abilities.

All these movements are performed with an arm swing. In order to return the long ball, a tennis player sometimes has to reach out or "run up" to it. All these actions require high joint mobility.

During the scoring, a tennis player hits the ball as many times as is required to score a point. When this process is taking too long, the ATP resynthesis is supported by the glycolytic mechanism.

Factor II involved the speed-strength capabilities of the upper and lower limb muscles, necessary for a tennis player, primarily, to perform a serve, jump up to hit the ball at the high points, accelerate faster, display power. The power indicators and time to reach the maximum power closely correlate with the competitive success rate.

Factor III - aerobic-anaerobic abilities - included the cardiac performance indicator, which is closely related to the competitive success rate; the indicator that characterizes endurance during the short point play, as well as latent time to choose a counteraction. No wonder the world’s top tennis players advise to never change the initial decision, and if there is an opportunity - to make an anticipatory decision, having thought several moves ahead. This is especially true in regard to returns.

Factor IV – alactic anaerobic capacity – included the indicators that determine its value, namely, the time to withhold the maximum power during the 10-sec cycle ergometer exercise, 10-sec work, the indicator of the speed-strength abilities displayed in stressful situations. That is exactly how they are displayed in practice during the competitive match.

Factor V - coordination abilities - is comprised of the spatial accuracy of movements and response time during speed-strength movements. Virtually any display of coordination abilities is associated with the manifestation of some other physical qualities and much too often with agility. For instance, the speed of motor action reorganization, response rate.

The results obtained during the study indicate that such factors were difficult to identify in tennis, unlike other game and cyclic sports [3-5], associated with the display of relatively independent physical abilities and qualities. In this regard, the structure of the tennis players’ physical fitness has more in common with that of wrestlers. For example, Factor I of the physical and functional fitness of female wrestlers includes 20 reliable indicators [6].

The most important of the specified factors is Factor I - special working capacity, which included the indicators of five physical qualities, some of which are not interrelated. In terms of this factor, it is endurance indicators that play the key role. All three energy sources are engaged in ensuring efficient work in tennis. Thus, Factor I presents the indicators of two of them. Moreover, there is a strong and significant correlation between the indicators of aerobic performance, characterizing its capacity, power and efficiency:

- correlation coefficient between MOC (ml / kg) and AMT (ml/kg) is 0.850;

- between MOC (ml/kg) and V (km/h): 0.750;

- between AMT (ml/kg) and V (km/h): 0.731;

- between t_work. (min) and IPC (ml/kg): 0.606;

- between t_work. (min) and V (km/h): 0.807.

In addition, the aerobic power, characterized by the high level of correlation with the competitive success rate, is also associated with Factor III. It is with this factor, as well as with Factor IV, that the endurance indicators characterizing alactic anaerobic working capacity are also associated.

The second most important component of Factor I is speed abilities, which two forms (speed of a single movement and acceleration speed) are in a close statistically significant correlation with the competitive success rate. The speed abilities indicator, namely the reaction rate, is presented in Factors III and V.

The third most important quality is speed-strength abilities, which completely constitute Factor II, where three indicators correlate with the competitive success rate. One indicator is associated with Factor I, another - with Factor IV. The results obtained should be considered when planning and implementing the training programs in separate links of the "static" and "dynamic" aspects of the training structure [7].

Conclusions:

• A factorial analysis under the study made it possible to find five key physical and functional fitness factors. The most influential factor includes 12 criteria to rate the physical qualities.
• The factorial analysis under the study enabled to find 5 key physical and functional fitness factors in tennis. These five factors accounted for 75% of the total sample variance
• Not all the specified factors are associated with the display of relatively independent physical qualities and abilities. Thus, Factor I - special working capacity was marked by the manifestation of five physical qualities.
• Special physical and functional fitness may largely be rated by the classified endurance types (48%) and the speed (28%) and speed-strength (8%) rates.
• As far as the endurance types are concerned, the key role is played by the aerobic capacity related endurance, with improvements in the aerobic capacity being critical for the working capacity maintenance for the whole match time.
• Progress of elite tennis players was found to depend rather on the harmonized development of the sport-specific physical qualities and skills pivotal for the competitive success than on some specific physical quality, regardless of how important the latter is for the competitive progress.

References

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6. Platonov V.N. Issledovanie sportivnoy trenirovki v plavanii kak tselostnogo slozhnoorganizovannogo objekta [Study of swimming training as integral complex object]. Doct. diss. Abstract (Hab.). Moscow, 1977, 57 p.
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Abstract

Objective of the study was to analyze the key aspects of the physical and functional fitness factors in the national tennis elite. The 17-23 year-old (n=36) elite tennis players were sampled for the study. A factorial analysis under the study made it possible to find five key physical and functional fitness factors. The most influential factor includes 12 criteria to rate the physical qualities. Special physical and functional fitness may largely be rated by the classified endurance types (48%) and the speed (28%) and speed-strength (8%) rates. As far as the endurance types are concerned, the key role is played by the aerobic capacity related endurance, with improvements in the aerobic capacity being critical for the working capacity maintenance for the whole match time. Progress of elite tennis players was found to depend rather on a harmonized development of the sport-specific physical qualities and skills pivotal for the competitive success than on some specific physical quality, regardless of how important the latter is for the competitive progress.