Influence of a 100-mile ultramarathon on the heart rate and the heart rate variability

Abstract

INTRODUCTION: The aim of this study was to investigate the impact of an ultra-marathon (UM) with a distance of 100 miles on heart rate (HR) and heart rate variability (HRV). METHODS: Altogether, 28 runners (25 men and 3 women) received a 24-hour long-term ECG one week before the UM (U1), immediately after (U2) and after a week of recovery (U3). The influence of age, body mass index (BMI), HR and HRV on the run time as well as recovery were investigated. RESULTS: A rise in the baseline heart rate accompanied by a significant drop in SDNN values ​​(the standard deviation of all normal RR intervals) was found. Except for the age of the runners, BMI, HF and HRV did not predict the competition time. Full return of HRV to the athlete’s individual baseline did not occur within one week. There were no significant differences between finishers and non-finishers in analyzed parameters. CONCLUSION: The present results show that a 100-mile run leads to an increase in sympathetic activity and thus to an increase in heart rate and a decrease in HRV. In addition, HRV seems to be a suitable parameter to evaluate full recovery after a 100-mile run.