{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,7]],"date-time":"2025-11-07T13:28:17Z","timestamp":1762522097309,"version":"build-2065373602"},"reference-count":41,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2017,12,1]],"date-time":"2017-12-01T00:00:00Z","timestamp":1512086400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010198","name":"MINECO","doi-asserted-by":"publisher","award":["TEC2014-60337-R"],"award-info":[{"award-number":["TEC2014-60337-R"]}],"id":[{"id":"10.13039\/501100010198","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>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.<\/jats:p>","DOI":"10.3390\/e19120658","type":"journal-article","created":{"date-parts":[[2017,12,1]],"date-time":"2017-12-01T12:30:16Z","timestamp":1512131416000},"page":"658","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Assessment of Heart Rate Variability during an Endurance Mountain Trail Race by Multi-Scale Entropy Analysis"],"prefix":"10.3390","volume":"19","author":[{"given":"Montserrat","family":"Vallverd\u00fa","sequence":"first","affiliation":[{"name":"Department of ESAII, Centre for Biomedical Engineering Research, Universitat Polit\u00e8cnica de Catalunya, 08028 Barcelona, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Bioingenier\u00eda, Biomateriales y Nanomedicina (CIBER-BBN), 08028 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aroa","family":"Ruiz-Mu\u00f1oz","sequence":"additional","affiliation":[{"name":"Department of ESAII, Centre for Biomedical Engineering Research, Universitat Polit\u00e8cnica de Catalunya, 08028 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Emma","family":"Roca","sequence":"additional","affiliation":[{"name":"Department of ESAII, Centre for Biomedical Engineering Research, Universitat Polit\u00e8cnica de Catalunya, 08028 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pere","family":"Caminal","sequence":"additional","affiliation":[{"name":"Department of ESAII, Centre for Biomedical Engineering Research, Universitat Polit\u00e8cnica de Catalunya, 08028 Barcelona, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Bioingenier\u00eda, Biomateriales y Nanomedicina (CIBER-BBN), 08028 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ferran A.","family":"Rodr\u00edguez","sequence":"additional","affiliation":[{"name":"INEFC-Barcelona Sport Sciences Research Group, Institut Nacional d\u2019Educaci\u00f3 F\u00edsica de Catalunya, Universitat de Barcelona, 08038 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alfredo","family":"Irurtia","sequence":"additional","affiliation":[{"name":"INEFC-Barcelona Sport Sciences Research Group, Institut Nacional d\u2019Educaci\u00f3 F\u00edsica de Catalunya, Universitat de Barcelona, 08038 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexandre","family":"Perera","sequence":"additional","affiliation":[{"name":"Department of ESAII, Centre for Biomedical Engineering Research, Universitat Polit\u00e8cnica de Catalunya, 08028 Barcelona, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Bioingenier\u00eda, Biomateriales y Nanomedicina (CIBER-BBN), 08028 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,12,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1111\/j.1542-474X.2005.10101.x","article-title":"Heart rate variability: Measurement and clinical utility","volume":"10","author":"Kleiger","year":"2005","journal-title":"Ann. Noninvasive Electrocardiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1031","DOI":"10.1007\/s11517-006-0119-0","article-title":"Heart rate variability: A review","volume":"44","author":"Rajendra","year":"2006","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_3","first-page":"255","article-title":"On the quantification of heart rate variability spectral parameters using time-frequency and time-varying methods","volume":"367","author":"Mainardi","year":"2009","journal-title":"Philos. Trans. A Math. Phys. Eng. Sci."},{"key":"ref_4","first-page":"89","article-title":"Long-term HRV in critically ill pediatric patients: Coma versus brain death","volume":"41","author":"Rocha","year":"2014","journal-title":"Comput. Cardiol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Voss, A., Schroeder, R., Heitmann, A., Peters, A., and Perz, S. (2015). Short-Term Heart Rate Variability. Influence of Gender and Age in Healthy Subjects. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0118308"},{"key":"ref_6","unstructured":"Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology (1996). Heart rate variability: Standards of measurement, physiological interpretation and clinical use. Circulation, 93, 1043\u20131065."},{"key":"ref_7","first-page":"277","article-title":"Methods derived from nonlinear dynamics for analyzing heart rate variability","volume":"367","author":"Voss","year":"2009","journal-title":"Philos. Trans. A Math. Phys. Eng. Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"021915","DOI":"10.1103\/PhysRevE.85.021915","article-title":"Multiscale multifractal analysis of heart rate variability recordings with a large number of occurrences of arrhythmia","volume":"85","author":"Baranowski","year":"2012","journal-title":"Phys. Rev. E"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1097\/01.jsm.0000244610.34594.07","article-title":"Heart rate variability, blood pressure variability, and baroreflex sensitivity in overtrained athletes","volume":"16","author":"Baumert","year":"2006","journal-title":"Clin. J. Sport Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"021906","DOI":"10.1103\/PhysRevE.71.021906","article-title":"Multiscale entropy analysis of biological signals","volume":"71","author":"Costa","year":"2005","journal-title":"Phys. Rev. E"},{"key":"ref_11","first-page":"1223","article-title":"Clinical impact of evaluation of cardiovascular control by novel methods of heart rate dynamics","volume":"367","author":"Huikuri","year":"2009","journal-title":"Philos. Trans. A Math. Phys. Eng. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1080\/03091900601050862","article-title":"Cardiac state diagnosis using higher order spectra of heart rate variability","volume":"32","author":"Chua","year":"2008","journal-title":"J. Med. Eng. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"948","DOI":"10.3389\/fnhum.2014.00948","article-title":"Fetal autonomic brain age scores, segmented heart rate variability analysis, and traditional short term variability","volume":"8","author":"Hoyer","year":"2014","journal-title":"Front. Hum. Neurosci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"364","DOI":"10.3389\/fphys.2013.00364","article-title":"Short-term vs. long-term heart rate variability in ischemic cardiomyopathy risk stratification","volume":"4","author":"Voss","year":"2013","journal-title":"Front. Physiol."},{"key":"ref_15","first-page":"10","article-title":"Heart Rate Turbulence: A Review","volume":"3","author":"Watanabe","year":"2003","journal-title":"Indian Pacing Electrophysiol. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1007\/s00421-011-2079-9","article-title":"Possibilities and limitations of the polar RS800 in measuring heart rate variability at rest","volume":"112","author":"Hasson","year":"2012","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1007\/s00421-015-3303-9","article-title":"Validity of the Polar V800 heart rate monitor to measure RR intervals at rest","volume":"116","author":"Giles","year":"2016","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"793","DOI":"10.1038\/sj.ijo.0800928","article-title":"Autonomic responsiveness to acute cold exposure in obese and non-obese young women","volume":"23","author":"Matsumoto","year":"1999","journal-title":"Int. J. Obes. Relat. Metab. Disord."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"26","DOI":"10.4236\/jbbs.2013.31004","article-title":"Heart rate variability, standard of measurement, physiological interpretation and clinical use in mountain marathon runners during sleep and after acclimatization at 3480 m","volume":"3","author":"Gritti","year":"2013","journal-title":"J. Behav. Brain Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1089","DOI":"10.1016\/S0002-9149(99)80309-9","article-title":"The effects of emotions on short-term power sectrum analysis of heart rate variability","volume":"76","author":"McCraty","year":"1995","journal-title":"Am. J. Cardiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.1109\/TBME.1986.325694","article-title":"Power spectral analysis of heart rate variability in sudden cardiac death: Comparison to other methods","volume":"33","author":"Myers","year":"1986","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"H1171","DOI":"10.1152\/ajpheart.00534.2009","article-title":"Cardiac autonomic neural remodeling and susceptibility to sudden cardiac death: Effect of endurance exercise training","volume":"297","author":"Billman","year":"2009","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1395","DOI":"10.1016\/S0735-1097(01)01171-8","article-title":"Prediction of sudden cardiac death by fractal analysis of heart rate variability in elderly subjects","volume":"37","author":"Huikuri","year":"2001","journal-title":"J. Am. Coll. Cardiol."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Arroyo-Carmona, R.E., L\u00f3pez-Serrano, A.L., Albarado-Iba\u00f1ez, A., Mendoza-Lucero, F.M., Medel-Cajica, D., L\u00f3pez-Mayorga, R.M., and Torres-J\u00e1come, J. (2016). Heart Rate Variability as Early Biomarker for the Evaluation of Diabetes Mellitus Progress. J. Diabetes Res.","DOI":"10.1155\/2016\/8483537"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"889","DOI":"10.2165\/00007256-200333120-00003","article-title":"Heart rate variability in athletes","volume":"33","author":"Aubert","year":"2003","journal-title":"Sports Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1007\/s40279-013-0071-8","article-title":"Training adaptation and heart rate variability in elite endurance athletes: Opening the door to effective monitoring","volume":"43","author":"Plews","year":"2013","journal-title":"Sports Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1531","DOI":"10.3892\/etm.2016.3104","article-title":"The role of heart rate variability in sports physiology","volume":"11","author":"Dong","year":"2016","journal-title":"Exp. Ther. Med."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"73","DOI":"10.3389\/fphys.2014.00073","article-title":"Monitoring training status with HR measures: Do all roads lead to Rome?","volume":"5","author":"Buchheit","year":"2014","journal-title":"Front. Physiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1120","DOI":"10.1097\/00005768-200107000-00009","article-title":"Intense endurance training on heart rate and blood pressure variability in runners","volume":"33","author":"Portier","year":"2001","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1007\/s00421-007-0552-2","article-title":"Endurance training guided individually by daily heart rate variability measurements","volume":"101","author":"Kiviniemi","year":"2007","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1055\/s-2004-817878","article-title":"Comparison of Polar 810 and an ambulatory ECG system for RR interval measurement during progressive exercise","volume":"26","author":"Kingsley","year":"2005","journal-title":"Int. J. Sports Med."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1002\/clc.4960210810","article-title":"Ischemia-induced reflex sympathoexcitation during recovery period after maximal treadmill exercise testing","volume":"21","author":"Dilaveris","year":"1998","journal-title":"Clin. Cardiol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1139\/apnm-2016-0093","article-title":"Muscle damage, physiological changes, and energy balance in ultra-endurance mountain-event athletes","volume":"41","author":"Alacid","year":"2016","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1080\/17461391.2015.1004373","article-title":"A pilot study on quantification of training load: The use of HRV in training practice","volume":"16","author":"Saboul","year":"2016","journal-title":"Eur. J. Sport Sci."},{"key":"ref_35","first-page":"170","article-title":"A system model of training for athletic performance","volume":"7","author":"Bannister","year":"1975","journal-title":"Aust. J. Sports Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1080\/17461391.2014.922621","article-title":"Training load quantification in elite swimmers using a modified version of the training impulse method","volume":"15","author":"Feriche","year":"2015","journal-title":"Eur. J. Sport Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2297","DOI":"10.1073\/pnas.88.6.2297","article-title":"Approximate entropy as a measure of system complexity","volume":"88","author":"Pincus","year":"1991","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"H2039","DOI":"10.1152\/ajpheart.2000.278.6.H2039","article-title":"Physiological time-series analysis using approximate entropy and sample entropy","volume":"278","author":"Richman","year":"2000","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1139\/apnm-2014-0263","article-title":"Psychophysiological response and energy balance during a 14-h ultraendurance mountain running event","volume":"40","year":"2015","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1728","DOI":"10.1152\/japplphysiol.00487.2005","article-title":"Hemodynamic and autonomic changes induced by Ironman: Prediction of competition time by blood pressure variability","volume":"99","author":"Gratze","year":"2005","journal-title":"J. Appl. Physiol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1152\/jappl.1996.81.3.1223","article-title":"Effects of acute exposure to simulated altitude on heart rate variability during exercise","volume":"81","author":"Yamamoto","year":"1996","journal-title":"J. Appl. Physiol."}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/19\/12\/658\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:52:19Z","timestamp":1760208739000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/19\/12\/658"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,12,1]]},"references-count":41,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2017,12]]}},"alternative-id":["e19120658"],"URL":"https:\/\/doi.org\/10.3390\/e19120658","relation":{},"ISSN":["1099-4300"],"issn-type":[{"type":"electronic","value":"1099-4300"}],"subject":[],"published":{"date-parts":[[2017,12,1]]}}}