Heart rate variability in cross-country skiers with different level of maximum oxygen consumption

AIM: This research aimed to study heart rate variability (HRV) in cross-country skiers with different levels of maximal oxygen consumption (VO2max). MATERIALS AND METHODS: HRV analysis was carried out using the Ecosan-2007 (Medical Computer Systems, Russia) complex in 52 cross-country skiers from the Komi Republic team (candidates for master of sports and master of sports of Russia). The Oxycon Pro ergospirometric system (Erich Jaeger, Germany) was used to calculate VO2max. To identify the HRV patterns in individuals with different levels of VO2max, volunteers were divided into two groups: with VO2max up to 4400 ml/min (n=27) and over 4400 ml/min (n=25). The MannWhitney U-test was used to ascertain whether the differences between groups were statistically significant. A Spearman correlation test was used to analyze the relationship between the VO2max and HRV. RESULTS: Athletes with different levels of VO2max showed significant differences in several HRV indicators as follows: absolute values of LF and VLF waves, the relative value of HF waves, LF/HF, and IC indices. Correlation analysis indicated the presence of a significant negative correlation between the absolute values of VO2max and MxDMn, MxRMn, LF/HF, IC, power of LF, and LF%. VLF waves. Furthermore, a positive correlation was observed between VO2max and HF%. The relative values of the VO2max/kg showed a significant negative correlation with MxRMn, TP, LF, VLF, LF/HF, and IC; and positive with HF%. CONCLUSION: In cross-country skiers, a significant correlation was identified between VO2max and HRV parameters. Compared to Athletes with lower VO2max, those with higher VO2max had a more efficient mode of heart rate regulation.