VOLLEYBALL PLAYERS TRAINING INTENSITY MONITORING THROUGH THE USE OF SPECTRAL ANALYSIS OF HEART RATE VARIABILITY DURING A TRAINING MICROCYCLE
Acta Univ. Palacki. Olomuc., Gymn
INTRODUCTION Sports performance in volleyball is infl uenced by a num ber of qualities, skills, and the functional states of players, which come out in a match, including jump height, the power and precision of a hit, and the speed or timing of a move. Volleyball players in diff erent spe-cializations are required to meet specifi c demands in terms of movement behaviour and skills performance. It is clear that knowledge of particular players' reactions to training or a match load enables them
... load enables them to optimize their training programmes. Therefore one of the key con ditions for achieving good sports performance is the consistent individualization of their training load (Alberda, 1995; Polglaze & Dawson, 1992). Spectral analysis of heart rate variability (SA HRV), based on methods of frequency analysis of R-R intervals from ECG records, gives us information on the autono-mic regulation of cardiac activity. This autonomic nervous system (ANS) regulation signifi cantly aff ects the adaptation of an athlete's organism to training and the reby also his/her sports performance. The high and ba lanced activity level of both ANS branches is an indicator of a good adaptability level and optimal readiness for sports performance. On the other hand, a long time low activity level of ANS (mainly parasympathetic) and a signifi cant prevalence of sympathetic activity results in a decrease of training adaptability and of sports performance mostly as well (Bosquet, Papelier, Léger, & Legros, 2003; Jakubec, 2005; Stejskal, 2002; Stejskal, 2008). If the intensity and volume of the previous training exceed the actual adaptation capacity of an athlete, his ANS is reduced and shifted towards sympathetic activity. The actual activity of ANS can consequently be a cause of the fact that the same training can induce diff erent reactions in the same athlete. The result then can be exceeding of the actual training capacity or its insuffi cient utilization (Stejskal, 2004). BACKGROUND: Volleyball players in diff erent specializations are required to meet specifi c demands in terms of movement behaviour and skills performance. These specifi c demands need to be individualized according to the training ability level (adaptability to sports training) of particular players, which is mainly dependent on the activity of the autonomic nervous system (ANS). Spectral analysis of heart rate variability (SA HRV) gives us information on cardiac activity regulation, where the activity of ANS participates in a signifi cant way. Longitudinal assessment of SA HRV within a certain part of a training period can help us to observe the dynamics of the ANS activity and adaptability (training ability) changes of an observed player to training. OBJECTIVE: The goal of the work was to verify the possibility of volleyball players' training load optimalization during a one week training microcycle based on the longitudinal observation of dynamics of SA HRV complex indices. METHODS: The SA HRV method was used for the evaluation of autonomic cardiac regulation. The study group consisted of eight volleyball players who took part in 28 training sessions focused on conditioning and volleyball skills development. During the microcycle, there were 7 HRV examinations. RESULTS: The results demonstrated that notable and considerably varied changes in the activity of ANS in players were assessed owing to both training and extra-training stimuli. The results in two players show a high activity of ANS which enables them to increase their training intensity. Four players achieved average values of their ANS activity, which refl ects a corresponding training load. In the last two players we found a very low level of their ANS activity and it refers to their reduced adaptability to the training load, which was too high for them. CONCLUSION: The presented results support the necessity of the individualization of, at least a part of, team training. Such an optimalization and increase of training process effi ciency should lead to a sports performance improvement , also in team sports games.