In sports medicine, heart rate variability (HRV) is generally used to assess adaptation to endurance training. Our purpose was to study the follow-up of the training adaptability to the loads for hockey players during two top-level international competitions, analysing changes in HRV. The study involved 7 hockey players of the Spanish national team during the 2006th World Cup Jockey and during a preparatory period for Beijing Olympic Games (2008) (age 24,7 ± 4,6). The players agreed to HRV analysis being done before several international matches and trainings. HRV was analyzed with time domain (RMSSD and PNN50) and spectral domain (HF, LF and LF / HF) methods from RR intervals, recorded for each session during 5 minutes in stable supine resting (OmegaWave System). At the 2006th World Cup hockey 7 matches were studied, and the results show that RMSSD, PNN50 and HF decrease progressively throughout the tournament (MANOVA, p <.05). LF and LF / HF show a progressive increase (p <.05). Comparing a match of the World Cup (2006) with a training session of the pre-Olympic preparation (2008), players have positive correlations for the parameters RMSSD (rho=.829, p =.042) and LF (rho =.943; p =.005). According to the Wilcoxon Test, the values for the players in the World Cup for RMSSD, PNN50 and HF (p<.05) were lower, and for LF / HF (p<.05) were higher than in the pre-Olympic preparation. These data suggest that in a competition with many matches (World Cup), HRV and parasympathetic activity have a gradually decrement and, at the same time, sympathetic activity increases, indicating a disruption in the loads adaptation and an increase in the fatigue level. After two years, the positive correlations suggest that the analysis of HRV shows consistent results in the pre-Olympic preparation. As they are training sessions, there is a better adaptation to the loads and a lower fatigue level. HRV analysis is a promising tool that may expand in the follow-up of elite athletes. It can be a good individual marker of the cardiovascular adaptability to the effort. It can help manage resting time and prevent overtraining in the competitions high performance is required during long-term periods.
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