Influence of a 100-mile Ultramarathon on Heart Rate and Heart Rate Variability

Abstract

BACKGROUND: 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: 28 runners (25 males and 3 females) underwent 24-hour Holter ECG monitoring one week before the UM (U1), immediately after (U2) the UM 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 (18.98%) immediately after the run accompanied by a significant drop in the standard deviation of all normal RR intervals (SDNN) (7.12%) one week after. Except for the age of the runners, BMI, HR and HRV showed no influence on the competition time. Full return of HRV to the athletes´ individual baseline did not occur within one week. There were no significant differences between finishers and non-finishers in analysed 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 might be a suitable parameter to evaluate full recovery after a 100-mile run.