A.V. Gusev, associate professor, Ph.D.
A.S. Ivanov
Military Institute of Physical Culture, St. Petersburg

Key words: swimming speed, swimming pace, swimming «step», stroke density, training process.

Relevance. The swimming ability is one of vital skills. Swimming is one of the most important means of physical education, so it is included in the content of preschool institutions, comprehensive and secondary schools and higher educational institutions. However, according to the data the percentage of children who can swim is low. Successful mastery of a motor action, namely the supported stroke in the initial training stage, will help significantly increase the level of swimming skills.

The purpose of the study was to provide experimental verification of the effectiveness of swimming training program for children at the phase of basic training by controlling the main characteristics of the swimming technique of children of different ages (speed, pace, “step”, stroke density).

Materials and methods. The experiment was organized on the basis of sports therapeutic swimming groups of the children's sport school "Kometa" in the swimming pool of Military Institute of Physical Culture (St. Petersburg) from December 2013 to May 2014 during swimming classes.

According to the conventional methodology, a group of exercises for children to get used to water implies introducing children into the physical properties of water, developing their correct breathing skills and taking a horizontal position in the water.

The initial training (1-24 classes) was based on the principle of priority of studying of the basic biomechanical element - supported stroke (Grinev V.T., Pogrebnoy A.I., Kostyuk Yu.I., Zvyagintseva T.M., 1990). Owing to a well mastered supported stroke a child can not only float on the water, but also move his body through the water later on.

In order to help children master the skill to find support, in our methodology we used:

• simulation exercises on land: simulation of a stroke (after demonstration), with teacher’s correction, with support, by the specified stencil, in front of the mirror, without visual control, etc.;
• the exercises performed in water beside the fixed support (introduced starting from the 2nd-4th classes) were as follows:
• a) facing the support (by the overflow gutter or skirting board of the swimming pool);
• b) standing with one's side to the skirting board of the swimming pool in the squat position, tuck position, back floating position (in these cases, the subject performed the supported stroke with one hand and held the support with the other);
• c) standing with one's back to the skirting board of the swimming pool (in the squat/ tuck position);
• with the use of special shovels of various forms to avoid the most common mistakes (performed in the squat position, tuck position, beside the support, in the front and back floating positions, etc.);
• performance of the supported stroke with different speed, amplitude (swing), rhythmic pattern;
• transition from the tuck position to back floating, front floating positions, rotation (performed on the count of 5, 10, 15 and so on);
• performance of the task to float on the water in different positions by series (threefold 20-second floating with 10-second rest) with gradual increase in the number of reps and time of floating (performed with and without the shovels).

The proposed training program involved the implementation of: from the 25^th class - a set of exercises used to learn different modifications of the supported stroke. We determined these strokes in the form of the following directives: "clap behind head", "swim feet first", "swim head first", "perform under-chest supported stroke".

The program exercises from the third set implied learning the basics of the competitive swimming techniques - front crawl, back crawl.

We assumed that mastering of the stroke movements in different positions and the skill to find and use support in these positions would provide for moving to mastering of the competitive swimming technique.

During the 25^th-27^th classes, 15-20% of the class was dedicated to mastering of the new variants of the supported stroke. Further on, these exercises were implemented as compensatory swimming.

Results and discussion. The research results revealed no significant differences in the floating time among all children from the experimental groups when using active arm movements in the first classes. However, by the 12^th class they mastered the skill to float on the water using the supported stroke, both in the tuck and back floating positions. While in the control groups a little over 60% of children could float on the water in the tuck position using active arm movements and 40% - in the back floating position. Besides, the children from the experimental groups were able to float on the water much longer than the children from the control groups (Table 1). With that, in the control groups the floating time either did not increase (1^st and 3^rd formers (boys) or increased threefold (2^nd formers (girls).

In the experimental groups the floating time in the tuck position increased by more than 6.6, 5.7 and 5.5 times for the 1^st, 2^nd and 3^rd formers (boys) respectively. As for the girls from the experimental groups, it increased by 6.9, 10.4 and 5.5 times accordingly.

Having studied further dynamics of the increase of the given index during the 16^th, 20^th and 24^th classes, we noticed that the rate of increase had fallen insignificantly, but nevertheless it still equaled 140-200% during each testing.

Therefore, by the 24^th class the initial floating time in the tuck position had changed among the children from the experimental groups: boys - 22.2, 40.3 and 21.1 times for the 1^st, 2^nd and 3^rd formers respectively; girls -  35.7, 79.1 and 46.5 times for the 1^st, 2^nd and 3^rd formers accordingly. In all the cases the differences were statistically significant (Р<0,05).

Тable 1. Indices of floating time (sec) in the tuck position using supported stroke (х+m)

Comments: E - experimental group, C - control group

Moreover, among the 2nd formers 56.2% of boys and 50% of girls could float on the water for more than 3 minutes. Among the 3rd formers the percentage was as follows: 100% of boys and 62% of girls. Some of the children (22% of the 2nd formers and 53% of the 3rd formers) were able to easily float using supported strokes for more than 5 minutes. Against the background of these indices, the floating time for the children from the control groups seems poor (8-12 seconds).

A similar pattern was observed when performing a supported stroke in the "back floating" position. Thus, by the 4^th class the children from the control and experimental groups could not float on the water in the specified position (Table 2).

Table 2. Indices of floating time (sec) in the back floating position using supported stroke (х+m)

In the 12^th class we observed some significant differences between the two groups in the back floating time.

The children from the control groups did the "back floating" exercise according to the conventional methodology. By the 12^th class this element had been mastered by 47.1% of the 1st formers (boys), 60% of the 2nd formers and 67% of the 3rd formers (boys). Among the girls these indices were lower (46.7%, 40% and 13.3% respectively). And their floating time was 5.1 seconds on the average (Table 2).

In the experimental groups, by the 12^th class each and all the children had already mastered the skill to float on the water in the specified position. Moreover, their floating time ranged from 28.4 seconds (in the 1st formers (girls) to 50.8 seconds (in the 2nd formers (boys). According to the testing conducted from then on during the 16th, 20th and 24th classes, the rate of increase of the given index was quite stable and equaled 140-200%.

By the 20th class, 26.1% of the 2^nd formers (boys), 29.4% of the 3^rd formers (boys), and 25.0% of the 3^rd formers (girls) were able to float on the water in the specified position for more than three minutes. By the 24^th class the percentage of such children had grown significantly: 60% of the 1st formers (boys), 91.3% of the 2^nd formers, 100% of the 3rd formers. Among the girls the percentage equaled 62.5%, 75% and 62.5% accordingly.

Besides, 56.5% of the 2^nd and 52.9% of the 3^rd formers (boys) were floating on the water for more than five minutes, and some of the children - even for more than 10 minutes. In the control groups, by the time this class was given, all the children had mastered the back float skill but they were able to keep this position only for 8-15 seconds.

Conclusion. The experimental results had proved practically the expediency and necessity of using supported stroke movements in various positions for mastering and enhancing the children’s sports swimming technique at the phase of basic training.

References

1. Bagin, N.A. Technique and order of learning sports swimming methods: study guide. – St. Petersburg: 40 SRIMD RF, 2004. – 145 P. (In Russian)
2. Grinyov, V.T. Biomechanical bases of learning swimming: study guide / V.T. Shrinev, A.I. Pogrebnoy, Yu.I. Kostyuk, T.M. Zvyagintseva. - Krasnodar, 1990. – 82 P. (In Russian)
3. Men'shutkina, T.G. Theory and methodology of health and fitness technologies of basic sports: guidance / St. Petersburg: Lesgaft SAPC, 2002. – 118 P. (In Russian)
4. Competitive swimming: a textbook for higher schools of physical culture / Ed. by N.Zh. Bulgakova. – Moscow: FON, 1996. – 430 P. (In Russian)

Corresponding author: vifk-nic@ya.ru, beast08@mail.ru