HEART RATE VARIABILITY IN CROSS-COUNTRY SKIERS WITH DIFFERENT LEVEL OF MAXIMUM OXYGEN CONSUMPTION

Abstract

AIM: The aim of the research was to study heart rate variability (HRV) in cross-country skiers with different levels of maximal oxygen consumption (VO2max). MATERIAL AND METHODS: The analysis of HRV 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). VO2max was measured using the Oxycon Pro ergospirometric system (Erich Jaeger, Germany). 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 significance of differences between groups was assessed using the MannWhitney U-test. A Spearman correlation test was used to analyze the correlation between the VO2max and HRV. RESULTS: Athletes with different levels of VO2max showed significant differences in a number of HRV indicators: absolute values of LF and VLF waves, relative value of HF waves, LF/HF and IC indices. Correlation analysis showed a significant negative correlation between the absolute values of VO2max and MxDMn, MxRMn, LF/HF, IC, power of LF and LF%, VLF waves, also a positive correlation between VO2max and HF% was noted. The relative values of the VO2max/kg had a significant negative correlation with MxRMn, TP, LF, VLF, LF/HF, IC and positive with HF%. CONCLUSION: In cross-country skiers a significant correlation was found between VO2max and HRV parameters. Athletes with higher VO2max showed a more economical mode of heart rate regulation than those with lower VO2max.