Assessment of Heart Rate Variability during an Endurance Mountain Trail Race by Multi-Scale Entropy Analysis

Abstract

Abstract:The aim of the study was to analyze heart rate variability (HRV) response to high-intensity exercise during a 35-km mountain trail race and to ascertain whether fitness level could influence autonomic nervous system (ANS) modulation. Time-domain, frequency-domain, and multi-scale entropy (MSE) indexes were calculated for eleven mountain-trail runners who completed the race. Many changes were observed, mostly related to exercise load and fatigue. These changes were characterized by increased mean values and standard deviations of the normal-to-normal intervals associated with sympathetic activity, and by decreased differences between successive intervals related to parasympathetic activity. Normalized low frequency (LF) power suggested that ANS modulation varied greatly during the race and between individuals. Normalized high frequency (HF) power, associated with parasympathetic activity, varied considerably over the race, and tended to decrease at the final stages, whereas changes in the LF/HF ratio corresponded to intervals with varying exercise load. MSE indexes, related to system complexity, indicated the existence of many interactions between the heart and its neurological control mechanism. The time-domain, frequency-domain, and MSE indexes were also able to discriminate faster from slower runners, mainly in the more difficult and in the final stages of the race. These findings suggest the use of HRV analysis to study cardiac function mechanisms in endurance sports.

Monitoring Stress–Recovery Balance with Heart Rate Variability and Perceptual Load Markers During a Competitive Micro-cycle in Elite Ski Mountaineers

“…5). This finding is in agreement with Vallverdú et al [48] who also evidenced the utility of Mean RRsu to predict performance in mountain trail runners racing at moderate altitude. Plews et al [26,27] also underlined the potential of RR interval analysis to better understand the relationship with individual performance in elite endurance athletes.…”

“…The linear increase of LF ARsu (nu) throughout the exposure of hypoxia and repeated racing may well reflect the ANS modulation towards SNS predominance during the competition and a relatively fast recovery afterward. Spectral indices are controversial in the current literature; while some authors support their use to provide sensitive information for training and/or competition in female well-trained cyclists [3], in elite swimmers [2,32,37], in elite cross-country skiers [40], or in the mountain trail race context [48], others did not observe noticeable changes in the LF index [19,25,35]. The present results suggest that intensified training loads and hypoxic stress may induce cumulative effects on HRV, evidenced by the normalized LF power spectrum, reflecting vagal tone withdrawal [2,32,37], as seen in Fig.…”

“…In these tight seasons, many athletes decrease their performance or become injured upon the appearance of various fatigue states [14]. In this context, resting heart rate variability (HRV) has shown to be a non-invasive and a valuable tool for monitoring training load and physiological fatigue, especially in elite endurance athletes competing in individual and team endurance sports [10,16,39,40,48].…”

Psychophysiological Stress Response of a Paralympic Athlete During an Ultra-Endurance Event. A Case Study

“…In this line, the sympathetic activation presented by the Paralympic athlete since the previous moments of the race showed an anticipatory anxiogenic response, also during the race an increase in sympathetic response was observed, as previous studies conducted in mountain ultraendurance runners [14], but with lower values of RMSSD, showing a higher impact of the ultraendurance race for the Paralympic athlete. The HRV seems to be an important tool to control, asses and predict sport performance, especially in ultraendurance events, since previous studies could differentiate fastest and lowest athletes in this probe only using this parameter [49], and it has been identified as an efficiency tool to control workload during training and physiological response in extreme ambient as well [50].…”

A complete psychophysiological profile of a Paralympic athlete in a ultraendurance

“…In this line, the sympathetic activation presented by the Paralympic athlete since the previous moments of the race showed an anticipatory anxiogenic response, also during the race an increase in sympathetic response was observed, as previous studies conducted in mountain ultraendurance runners [14], but with lower values of RMSSD, showing a higher impact of the ultraendurance race for the Paralympic athlete. The HRV seems to be an important tool to control, asses and predict sport performance, especially in ultraendurance events, since previous studies could differentiate fastest and lowest athletes in this probe only using this parameter [48], and it has been identified as an efficiency tool to control workload during training as well [49].…”