ORIGINAL ARTICLE  SPORT CARDIOLOGY 

The Journal of Sports Medicine and Physical Fitness 2020 October;60(10):1401-7

DOI: 10.23736/S0022-4707.20.10860-0

Copyright © 2020 EDIZIONI MINERVA MEDICA

language: English

Effects of a 75-km mountain ultra-marathon on heart rate variability in amateur runners

Alberto CALLEJA-ROMERO ¹ ✉, Isaac LÓPEZ-LAVAL ¹, Sebastian SITKO ¹, David HERNANDO ^{2, 3}, Germán VICENTE-RODRÍGUEZ ^{1, 4, 5, 6}, Raquel BAILÓN ^{2, 3}, Nuria GARATACHEA ^{1, 4, 5, 6, 7}

¹ Department of Physiatry and Nursing, Faculty of Health and Sport Science (FCSD), University of Zaragoza, Huesca, Spain; ² BSICoS Group, Aragon Institute of Engineering Research (I3A), IIS Aragón, University of Zaragoza, Zaragoza, Spain; ³ CIBER- Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain; ⁴ Growth, Exercise, Nutrition and Development Group, Faculty of Health and Sport Sciences, University of Zaragoza, Zaragoza, Spain; ⁵ Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBER-Obn), Madrid, Spain; ⁶ Instituto Agroalimentario de Aragón -IA2- (CITA-Universidad de Zaragoza), Zaragoza, Spain; ⁷ National Sports Council, Madrid, Spain

BACKGROUND: This study examined the effects of a mountain ultra-marathon (MUM) on the activity of the autonomous nervous system through heart rate variability (HRV) monitoring and determined whether this variable related to final performance.
METHODS: Heart rate and HRV were measured in eight male amateur runners (aged 37-60 years). Measurements were recorded before and after the event, in resting conditions, as well as continuously throughout the whole MUM. In addition, percentage (%) of heart rate reserve (HRres) and partial and total times during the race were analyzed.
RESULTS: Average heart rate (HRavg) measured at rest was increased after the event (+37%). Standard deviation of successive differences (SDSD) and the square root of the mean squared differences of successive NN intervals (RMSSD) were reduced after the MUM (-56% and -59%, respectively). There was a positive relationship between the frequency-domain index normalized low frequency power (PLFn) measured at rest before the event and race time (0.79) while there was a negative relationship between race time and the difference in HRavg before and after the event. In the last half of the event, there was a high correlation (Spearman coefficient of correlation >0.9) between race time and the standard deviation of the NN intervals (SDNN) registered during the race.
CONCLUSIONS: Autonomous cardiac regulation can be related to the performance in a mountain ultra-marathon. HRV monitoring could represent a practical tool for the evaluation of the relationship between the autonomous nervous system activity and performance in a mountain ultra-marathon.

KEY WORDS: Autonomic nervous system; Cardiovascular physiological phenomena; Heart rate; Exercise; Running