PhD, Associate Professor R.R. Abzalov¹
Dr.Biol., Associate Professor N.I. Abzalov¹
PhD, Associate Professor А.М. Valeev¹
Dr.Biol., Professor R.A. Abzalov¹
PhD, Associate Professor S.V. Abzalova²
PhD, Associate Professor R.A. Rusakov^1
1Kazan (Volga Region) Federal University, Kazan
²Kazan State Power Engineering University, Kazan

Keywords: speed qualities, racing skiers, heart rate, stroke volume, heart contractive functionality, muscular training.

Introduction. Skiing training has always been geared to form endurance [3, 4, 5]. However, in modern skiing sport sprint distance competitions arose requiring from athletes to display speed endurance. Therefore, racing skiers’ sports activity started to base on the speed and strength qualities. In terms of muscular training geared to develop endurance, the progress pace of the movement speed building component decreases, while that of speed endurance - increases.

Thanks to speed endurance one can perform a motor action in a certain mode, without reducing its performance efficiency, ensures continuous performance of motor actions at a constant speed [1, 2, 3, 4, 5, 6]. The study of the heart contractive functionality in modern racing skiers in the context of development of speed endurance is necessary for establishing the regularities of the cardiac functionality depending on their qualification. The foregoing stresses the relevance and novelty of the research on the heart contractive functionality in those engaged in the skiing training program during adaptation to speed endurance work.

Objective of the study was to identify the features of the heart pumping function in differently skilled racing skiers during adaptation to speed and speed endurance work.

Methods and structure of the study. The studies were conducted at the Theory and Methodology of Physical Culture and Sport Department and involved the students of the Specialized Children and Youth Skiing Sport School of Kazan. The subjects (103 people - males and females) were divided into 4 groups: the first one was made of the racing skiers belonging to the III sports category; the second one – of those belonging to the I category; the third one – of Candidate Masters of Sport (CMS); the fourth one – of Masters of Sports (MS). It takes on the average 8-9 years to reach the level of MS in cross-country skiing. The reference group consisted of the 10th and 11th-graders of a general education school (48 people - males and females), non-athletes. The heart contractive functionality was determined by means of recording a tetrapolar differentiated thoracic rheogram. Stroke volume was calculated by the formula of W.G. Kubicek (1974). A special device for determining the quantitative characteristics of the arm and hand movements with maximum rate per 10 seconds was made to study the movement speed and speed endurance. 

The device was installed at a height adjustable and comfortable for the testee; a laptop with the video recording function was placed in front of him/her. The camera recorded the testee performing an exercise. After the command “Ready, Go!” the subject, moving his/her hand up-and-down, started to perform the maximum number of touches of the top and bottom panels of the device. A corresponding light on the front of the device came on every time the subject touched the top or the bottom panels. Each case of lighting up corresponded to the subject’s movement, which was recorded by the camera. The exercise was performed during 10 seconds at the maximum pace.

The total number of touches in 10 seconds was determined based on the video recordings and was taken as an indicator of the subject’s maximum movement speed.

Speed endurance was assessed by the time of the test task performance at the set pace (75% of the maximum number of touches in 10 seconds). Speed endurance efficiency was determined by the ratio of the number of touches at the set pace to the number of touches equaling 75% of max in 10 seconds.

Results and discussion. In the reference group, the maximum number of touches of the top and bottom panels in 10 seconds equaled 77.00±1.56 for males, and 67.00±1.54 for females. During the muscular training, the III category racing skiers exceeded the non-athletes by 6 touches for males, and by 13 touches for females (P≤0.05). The athletes of the III to the I categories demonstrated the highest increase in the speed values: by 15 touches for males, and by 10 touches for females (P≤0.05). The speed increase rate decreases with the transition from one sports category to another: MS, as opposed to CMS, were proved to have lower movement speed – by 3 touches for males, and by 4 touches for females. Within the range from the III to the I sports category, the speed endurance increase rate in males was 4 seconds, and in females - 5.14 seconds (P≤0.05), from the I category to CMS - 1.4 and 1.5 seconds, respectively. In MS, in comparison with CMS, speed endurance increased during the 4.8 second for males, and 5.7 second for females. Consequently, it is improvement of the racing skiers’ athletic fitness that has a positive effect on their speed endurance building process: the higher the sports qualification, the more pronounced the increase in the speed endurance values.

The study of the heart contractive functionality in the racing skiers made it possible to reveal certain features. Heart rate of the III sports category athletes is decreased compared to those not doing sports. Upon the speed test completion, heart rate in the III category racing skiers recovered during the 3rd minute, while in the reference group – only by the 5th minute. Heart rate at rest in MS, both males and females, was lower by 10 bpm in comparison with the non-athletes (P≤0.05).

Stroke volume in the non-athletes equaled 49.81±1.96 ml for males, and 44.23±1.89 ml for females. The III category racing skiers, as opposed to the reference group, were registered to have increased stoke volume: by 35.85 ml for males, and 34.62 ml for females (P≤0.05). In MS stroke volume in males increased by 66.91 ml, in females - by 54.28 ml, compared to the non-athletes (Р≤0.05). Stroke volume recovery upon completion of the test was registered in the III category racing skiers as early as at the end of the 1st minute.

Consequently, during the muscular training, the racing skiers develop bradycardia and increased stroke volume. The cardiac activity of the representatives of this sport registered at rest is characterized by an extended diastolic pause, which creates the necessary conditions for the increase of myocardial contractility and systolic discharge.

Minute blood volume in male non-athletes was equal to 3.64±0.19 l/min, while in females - 3.33±0.21 l/min. In the III category racing skiers, in comparison with the non-athletes, MBV increased by 1.94 l/min for males, and by 1.88 l/min for females (P≤0.05). In MS, as compared to the non-athletes, MBV was higher by 2.56 l/min for males, and by 2.11 l/min for females. The difference between the MBV values in the males and females is statistically significant (P≤0.05).

It should be noted that the MBV increase in the racing skiers during training is mostly due to the stroke volume, rather than heart rate. Consequently, cardiac output is an important factor for enhancement of cardiac efficiency.

Therefore, the racing skiers’ adaptation to regular muscular training is determined by the steady growth of MBV, that is, depends on the heart contractive functionality.

Conclusion. Skiers’ heart contractive functionality, which determines the stroke volume rate, enhances with the improvement of their sport skills to an increasing degree, as opposed to the decreased heart rate. In general, the changes in the heart rate and stroke volume values in the racing skiers turned out to be less pronounced than those presented in the literature [2, 3, 7]. This is due to the fact that modern skiing sport is characterized by high intensity speed- and speed-endurance-building practices.

The training mode of skiers, geared primarily to develop general endurance, determines a slowdown in the process of formation of speed qualities. The racing skiers’ speed values decrease with the improvement of their physical fitness. At the same time, speed endurance and its efficiency increase in modern racing skiers during the muscular training. This, obviously, is due to the fact that sprint distance competitions are being fostered in modern skiing. Therefore, the training lessons plans imply speed- and speed-endurance-building motor tasks.

References

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Corresponding author: abzalov2004@mail.ru

Abstract

The study was designed to explore the heart contractive functionality in the speed endurance building process in the differently skilled racing skiers' training system. The heart contractive functionality was tested using tetrapolar chest rheograms during the test practices dominated by the speed and speed endurance building ones. The tests showed that the progress pace of the movement speed building component decreased and the speed endurance increased with the growing physical fitness rates. Variations of the heart rates and stroke volumes tested in the racing skiers' muscular training process were less expressed versus the prior study data. This progress was due to a variety of speed-building practices included in the training process to train the skiers for competitive ski sprints. A high priority is to be given to heart contractive functionality profiling studies in the context of speed- and speed-endurance-building practices in the junior athletes’ qualification and training system design initiatives.