Assessment of the effectiveness of the application of isometric exercises in the special strength preparation of qualified volleyball players

Аннотация

Objective of the study is to assess the effectiveness of the application of isometric exercises in the special strength preparation of qualified volleyball players.

Methods and structure of the study. Sixteen qualified male volleyball players (of a category not lower than Candidate for Master of Sport) aged 18-25 years took part in the research; they make up the main squad of the higher league team of the Autonomous Non-Profit Organisation ‘Volleyball Club Kama’ (Perm). The effectiveness of the application of isometric exercises was assessed by means of the following indicators: the height of the vertical jumps without and with an arm swing (cm), assessed by the method of tensometry using a ForceDecks dual force platform; the strength of the muscles of the hand and forearm for the left and right hands and the strength of the extensors of the trunk, assessed by the method of dynamometry (a DK hand dynamometer and a DS-200 back dynamometer); the time of performance of the control test ‘Plank’ (s); the distance in the control test ‘throw of a 1 kg ball from behind the head with two hands, seated’ (m); and the calculated data of the video analysis of official matches: the effectiveness of serves (%), the ‘height of the block’ (cm), the ‘percentage of blocks won’ (%) and the effectiveness of attacking hits (%). In the course of the mathematical processing of the results, the arithmetic mean and the standard deviation (x̄±σ), the indicator of dynamics (relative change, %) and the effect size (ES) were calculated.

Hypotheses about the significance of the statistical differences in the athletes’ indicators over the period of the study were tested by calculating the Wilcoxon test for the 5 % level of significance.

Results and conclusions. The application of isometric exercises ensures statistically significant gains in the indicators of the strength abilities of qualified volleyball players, including those manifested in jumps and those requiring strength endurance, and also ensures an increase in the effectiveness of their competitive activity (serves, blocking and attacking hits).