{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,17]],"date-time":"2026-04-17T21:35:11Z","timestamp":1776461711634,"version":"3.51.2"},"reference-count":46,"publisher":"IOP Publishing","issue":"6","license":[{"start":{"date-parts":[[2024,6,25]],"date-time":"2024-06-25T00:00:00Z","timestamp":1719273600000},"content-version":"vor","delay-in-days":24,"URL":"https:\/\/iopscience.iop.org\/page\/copyright"},{"start":{"date-parts":[[2024,6,25]],"date-time":"2024-06-25T00:00:00Z","timestamp":1719273600000},"content-version":"tdm","delay-in-days":24,"URL":"https:\/\/iopscience.iop.org\/info\/page\/text-and-data-mining"}],"content-domain":{"domain":["iopscience.iop.org"],"crossmark-restriction":false},"short-container-title":["Physiol. Meas."],"published-print":{"date-parts":[[2024,6,1]]},"abstract":"Abstract<\/jats:title>\n \n Objective.<\/jats:italic> The fact that ramp incremental exercise yields quasi-linear responses for pulmonary oxygen uptake (\n \n \n \n \n \n V<\/mml:mtext>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n <\/mml:mrow>\n \n O<\/mml:mtext>\n 2<\/mml:mn>\n <\/mml:msub>\n <\/mml:mrow>\n <\/mml:math>\n \n <\/jats:inline-formula>) and heart rate (HR) seems contradictory to the well-known non-linear behavior of underlying physiological processes. Prior research highlights this issue and demonstrates how a balancing of system gain and response time parameters causes linear \n \n \n \n \n \n V<\/mml:mtext>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n <\/mml:mrow>\n \n O<\/mml:mtext>\n 2<\/mml:mn>\n <\/mml:msub>\n <\/mml:mrow>\n <\/mml:math>\n \n <\/jats:inline-formula> responses during ramp tests. This study builds upon this knowledge and extracts the time-varying dynamics directly from HR and \n \n \n \n \n \n V<\/mml:mtext>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n <\/mml:mrow>\n \n O<\/mml:mtext>\n 2<\/mml:mn>\n <\/mml:msub>\n <\/mml:mrow>\n <\/mml:math>\n \n <\/jats:inline-formula> data of single ramp incremental running tests. Approach.<\/jats:italic> A large-scale open access dataset of 735 ramp incremental running tests is analyzed. The dynamics are obtained by means of 1st order autoregressive and exogenous models with time-variant parameters. This allows for the estimates of time constant (\u03c4<\/jats:italic>) and steady state gain (SSG) to vary with work rate. Main results.<\/jats:italic> As the work rate increases, \u03c4<\/jats:italic>-values increase on average from 38 to 132 s for HR, and from 27 to 35 s for \n \n \n \n \n \n V<\/mml:mtext>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n <\/mml:mrow>\n \n O<\/mml:mtext>\n 2<\/mml:mn>\n <\/mml:msub>\n <\/mml:mrow>\n <\/mml:math>\n \n <\/jats:inline-formula>. Both increases are statistically significant (p<\/jats:italic> < 0.01). Further, SSG-values decrease on average from 14 to 9 bpm (km\u00b7h\u22121<\/jats:sup>)\u22121<\/jats:sup> for HR, and from 218 to 144 ml\u00b7min\u22121<\/jats:sup> for \n \n \n \n \n \n V<\/mml:mtext>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n <\/mml:mrow>\n \n O<\/mml:mtext>\n 2<\/mml:mn>\n <\/mml:msub>\n <\/mml:mrow>\n <\/mml:math>\n \n <\/jats:inline-formula> (p<\/jats:italic> < 0.01 for decrease parameters of HR and \n \n \n \n \n \n V<\/mml:mtext>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n <\/mml:mrow>\n \n O<\/mml:mtext>\n 2<\/mml:mn>\n <\/mml:msub>\n <\/mml:mrow>\n <\/mml:math>\n \n <\/jats:inline-formula>). The results of this modeling approach are line with literature reporting on cardiorespiratory dynamics obtained using standard procedures. Significance.<\/jats:italic> We show that time-variant modeling is able to determine the time-varying dynamics HR and \n \n \n \n \n \n V<\/mml:mtext>\n \u02d9<\/mml:mo>\n <\/mml:mover>\n <\/mml:mrow>\n \n O<\/mml:mtext>\n 2<\/mml:mn>\n <\/mml:msub>\n <\/mml:mrow>\n <\/mml:math>\n \n <\/jats:inline-formula> responses to ramp incremental running directly from individual tests. The proposed method allows for gaining insights into the cardiorespiratory response characteristics when no repeated measurements are available.<\/jats:p>","DOI":"10.1088\/1361-6579\/ad56f7","type":"journal-article","created":{"date-parts":[[2024,6,11]],"date-time":"2024-06-11T18:46:25Z","timestamp":1718131585000},"page":"065008","update-policy":"https:\/\/doi.org\/10.1088\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Identifying time-varying dynamics of heart rate and oxygen uptake from single ramp incremental running tests"],"prefix":"10.1088","volume":"45","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9459-836X","authenticated-orcid":true,"given":"Jasper","family":"Gielen","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Loes","family":"Stessens","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Romain","family":"Meeusen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jean-Marie","family":"Aerts","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"266","published-online":{"date-parts":[[2024,6,25]]},"reference":[{"key":"pmeaad56f7bib1","doi-asserted-by":"publisher","first-page":"755","DOI":"10.1152\/jappl.1993.75.2.755","article-title":"O2 uptake kinetics and the O2 deficit as related to exercise intensity and blood lactate","volume":"75","author":"Barstow","year":"1993","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib2","doi-asserted-by":"publisher","first-page":"2081","DOI":"10.1152\/jappl.2001.90.6.2081","article-title":"V\u02d9O2 and heart rate kinetics in cycling: transitions from an elevated baseline","volume":"90","author":"Bearden","year":"2001","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib3","doi-asserted-by":"publisher","DOI":"10.3389\/fphys.2023.1178913","article-title":"Pattern of the heart rate performance curve in maximal graded treadmill running from 1100 healthy 18\u201365 Years old men and women: the 4HAIE study","volume":"14","author":"Birnbaumer","year":"2023","journal-title":"Front. Physiol."},{"key":"pmeaad56f7bib4","doi-asserted-by":"publisher","first-page":"511","DOI":"10.2165\/11599690-000000000-00000","article-title":"The oxygen uptake response to incremental ramp exercise: methodogical and physiological issues","volume":"42","author":"Boone","year":"2012","journal-title":"Sports Med."},{"key":"pmeaad56f7bib5","first-page":"61P","article-title":"Relationship of heart rate to physical work","volume":"197","author":"Brooke","year":"1968","journal-title":"J. Physiol."},{"key":"pmeaad56f7bib6","doi-asserted-by":"publisher","first-page":"1","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":"pmeaad56f7bib7","doi-asserted-by":"publisher","first-page":"56","DOI":"10.1152\/ajpheart.00335.2007","article-title":"Noninvasive assessment of cardiac parasympathetic function: postexercise heart rate recovery or heart rate variability?","volume":"293","author":"Buchheit","year":"2007","journal-title":"Am. J. Physiol. Heart. Circ. Physiol."},{"key":"pmeaad56f7bib8","doi-asserted-by":"publisher","first-page":"1","DOI":"10.3390\/app9091822","article-title":"Box-Jenkins transfer function modelling for reliable determination of VO2 kinetics in patients with COPD","volume":"9","author":"Buekers","year":"2019","journal-title":"Appl. Sci."},{"key":"pmeaad56f7bib9","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1080\/02640418808729792","article-title":"Kinetics of heart rate responses to exercise","volume":"6","author":"Bunc","year":"1988","journal-title":"J. Sports Sci."},{"key":"pmeaad56f7bib10","doi-asserted-by":"publisher","first-page":"347","DOI":"10.1007\/s00421-001-0556-2","article-title":"Oxygen uptake kinetics during treadmill running across exercise intensity domains","volume":"86","author":"Carter","year":"2002","journal-title":"Eur. J. Appl. Physiol."},{"key":"pmeaad56f7bib11","doi-asserted-by":"publisher","first-page":"547","DOI":"10.1152\/jappl.1989.67.2.547","article-title":"Influence of work rate on ventilatory and gas exchange kinetics","volume":"67","author":"Casaburi","year":"1989","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib12","doi-asserted-by":"publisher","first-page":"618","DOI":"10.1152\/jappl.1972.32.5.618","article-title":"Kinetics of cardiac output and respiratory gas exchange during exercise and recovery","volume":"32","author":"Davies","year":"1972","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib13","doi-asserted-by":"publisher","first-page":"1901","DOI":"10.1152\/japplphysiol.00024.2003","article-title":"The maximally attainable VO2 during exercise in humans: the peak vs. maximum issue","volume":"95","author":"Day","year":"2003","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib14","doi-asserted-by":"publisher","first-page":"2500","DOI":"10.1152\/jappl.1996.81.6.2500","article-title":"Effects of hypoxic hypoxia on O2 uptake and heart rate kinetics during heavy exercise","volume":"81","author":"Engelen","year":"1996","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib15","doi-asserted-by":"publisher","first-page":"68","DOI":"10.1152\/jappl.1973.35.1.68","article-title":"Cardiorespiratory transients in exercising man. II. Linear models","volume":"35","author":"Fujihara","year":"1973","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib16","doi-asserted-by":"publisher","first-page":"35","DOI":"10.1016\/S0169-2607(99)00009-7","article-title":"Heart rate dynamics during sinusoidal exercise: comparison of the control system between children and adults","volume":"60","author":"Fukuba","year":"1999","journal-title":"Comput. Methods Programs Biomed."},{"key":"pmeaad56f7bib17","doi-asserted-by":"publisher","first-page":"640","DOI":"10.1123\/ijspp.2021-0217","article-title":"Monitoring internal and external load during volleyball competition","volume":"17","author":"Gielen","year":"2022","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"pmeaad56f7bib18","doi-asserted-by":"publisher","first-page":"e215","DOI":"10.1161\/01.CIR.101.23.e215","article-title":"PhysioBank, PhysioToolkit, and PhysioNet: components of a new research resource for complex physiologic signals","volume":"101","author":"Goldberger","year":"2000","journal-title":"Circulation"},{"key":"pmeaad56f7bib19","doi-asserted-by":"publisher","first-page":"717","DOI":"10.1007\/s00421-021-04878-z","article-title":"Cardiorespiratory kinetics in exercise physiology: estimates and predictions using randomized changes in work rate","volume":"122","author":"Hoffmann","year":"2022","journal-title":"Eur. J. Appl. Physiol."},{"key":"pmeaad56f7bib20","doi-asserted-by":"publisher","first-page":"183","DOI":"10.1152\/jappl.1970.28.2.183","article-title":"Transient cardiac output response to multiple levels of supine exercise","volume":"28","author":"Jones","year":"1970","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib21","doi-asserted-by":"publisher","first-page":"1286","DOI":"10.1093\/bioinformatics\/btn107","article-title":"Linear time-varying models can reveal non-linear interactions of biomolecular regulatory networks using multiple time-series data","volume":"24","author":"Kim","year":"2008","journal-title":"Bioinformatics"},{"key":"pmeaad56f7bib22","doi-asserted-by":"publisher","DOI":"10.14814\/phy2.12970","article-title":"Gender differences in VO2 and HR kinetics at the onset of moderate and heavy exercise intensity in adolescents","volume":"4","author":"Lai","year":"2016","journal-title":"Physiol. Rep."},{"key":"pmeaad56f7bib23","doi-asserted-by":"publisher","first-page":"S406","DOI":"10.1080\/17461391.2012.708791","article-title":"Time-variant modelling of heart rate responses to exercise intensity during road cycling","volume":"14","author":"Lefever","year":"2014","journal-title":"Eur. J. Sport Sci."},{"key":"pmeaad56f7bib24","first-page":"61","article-title":"V\u02d9O2 and cardiac output during rest-exercise and exercise-exercise transients","volume":"83","author":"Leyk","year":"1994","journal-title":"Z. Kardiol."},{"key":"pmeaad56f7bib25","doi-asserted-by":"publisher","first-page":"e3476","DOI":"10.1073\/pnas.1401883111","article-title":"Robust efficiency and actuator saturation explain healthy heart rate control and variability","volume":"111","author":"Li","year":"2014","journal-title":"Proc. Natl Acad. Sci. USA"},{"key":"pmeaad56f7bib26","article-title":"System identification theory for user","author":"Ljung","year":"1987"},{"key":"pmeaad56f7bib27","doi-asserted-by":"publisher","first-page":"203","DOI":"10.3166\/ejc.7.203-219","article-title":"Estimating linear time-invariant models of nonlinear time-varying systems","volume":"7","author":"Ljung","year":"2001","journal-title":"Eur. J. Control"},{"key":"pmeaad56f7bib28","doi-asserted-by":"publisher","first-page":"1318","DOI":"10.1152\/jappl.1997.83.4.1318","article-title":"Acceleration of V\u02d9O2 kinetics in heavy submaximal exercise by hyperoxia and prior high-intensity exercise","volume":"83","author":"MacDonald","year":"1997","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib29","doi-asserted-by":"publisher","first-page":"157","DOI":"10.1080\/15438627.2021.1954513","article-title":"Heart rate recovery to assess fitness: comparison of different calculation methods in a large cross-sectional study","volume":"31","author":"Mongin","year":"2021","journal-title":"Res. Sports Med."},{"key":"pmeaad56f7bib30","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-020-69218-1","article-title":"Validity of dynamical analysis to characterize heart rate and oxygen consumption during effort tests","volume":"10","author":"Mongin","year":"2020a","journal-title":"Sci. Rep."},{"key":"pmeaad56f7bib31","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6579\/abbb6e","article-title":"The complex relationship between effort and heart rate: a hint from dynamic analysis","volume":"41","author":"Mongin","year":"2020b","journal-title":"Physiol. Meas."},{"key":"pmeaad56f7bib32","doi-asserted-by":"publisher","first-page":"972","DOI":"10.3389\/fphys.2018.00972","article-title":"Limitation of maximal heart rate in hypoxia: mechanisms and clinical importance","volume":"9","author":"Mourot","year":"2018","journal-title":"Front. Physiol."},{"key":"pmeaad56f7bib33","doi-asserted-by":"publisher","first-page":"891","DOI":"10.1111\/j.1469-7793.2001.t01-1-00891.x","article-title":"Influence of exercise intensity on the on- and off- transient kinetics of pulmonary oxygen uptake in humans","volume":"533","author":"\u00d6zyener","year":"2001","journal-title":"J. Physiol."},{"key":"pmeaad56f7bib34","author":"Pedegral","year":"2007"},{"key":"pmeaad56f7bib35","doi-asserted-by":"publisher","first-page":"933","DOI":"10.1002\/cphy.c100072","article-title":"Oxygen uptake kinetics","volume":"2","author":"Poole","year":"2012","journal-title":"Compr. Physiol."},{"key":"pmeaad56f7bib36","doi-asserted-by":"publisher","first-page":"R601","DOI":"10.1152\/ajpregu.00305.2022","article-title":"Changes of the cardiac baroreflex bandwidth during postural challenges","volume":"324","author":"Porta","year":"2023","journal-title":"Am. J. Physiol. Regul. Integr. Comp. Physiol."},{"key":"pmeaad56f7bib37","doi-asserted-by":"publisher","first-page":"203","DOI":"10.1002\/cphy.c090010","article-title":"Exercise: kinetic considerations for gas exchange","volume":"1","author":"Rossiter","year":"2011","journal-title":"Compr. Physiol."},{"key":"pmeaad56f7bib38","doi-asserted-by":"publisher","first-page":"100","DOI":"10.1007\/s00421-002-0690-5","article-title":"Oxygen uptake and heart rate kinetics during heavy exercise: a comparison between arm cranking and leg cycling","volume":"88","author":"Schneider","year":"2002","journal-title":"Eur. J. Appl. Physiol."},{"key":"pmeaad56f7bib39","doi-asserted-by":"publisher","first-page":"426","DOI":"10.2991\/jnmp.2008.15.s3.41","article-title":"A model of heart rate kinetics in response to exercise","volume":"15","author":"Stirling","year":"2008","journal-title":"J. Nonlinear Math. Phys."},{"key":"pmeaad56f7bib40","doi-asserted-by":"publisher","first-page":"121","DOI":"10.1152\/japplphysiol.00507.2015","article-title":"Constructing quasi-linear VO2 responses from nonlinear parameters","volume":"120","author":"Wilcox","year":"2016","journal-title":"J. Appl. Physiol."},{"key":"pmeaad56f7bib41","doi-asserted-by":"publisher","first-page":"203","DOI":"10.1016\/j.resp.2006.09.008","article-title":"Effects of baseline metabolic rate on pulmonary O2 uptake on-kinetics during heavy-intensity exercise in humans","volume":"156","author":"Wilkerson","year":"2007","journal-title":"Respir. Physiol. Neurobiol."},{"key":"pmeaad56f7bib42","doi-asserted-by":"publisher","first-page":"90","DOI":"10.1111\/sms.12381","article-title":"Exercise intensity prescription during heat stress: a brief review","volume":"25","author":"Wingo","year":"2015","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"pmeaad56f7bib43","doi-asserted-by":"publisher","first-page":"355","DOI":"10.1113\/jphysiol.1994.sp020365","article-title":"Dynamic asymmetries of cardiac output transients in response to muscular exercise in man","volume":"480","author":"Yoshida","year":"1994","journal-title":"J. Physiol."},{"key":"pmeaad56f7bib44","author":"Young","year":"2011"},{"key":"pmeaad56f7bib45","article-title":"The CAPTAIN toolbox","author":"Young","year":"2007"},{"key":"pmeaad56f7bib46","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1371\/journal.pone.0118263","article-title":"Modelling heart rate kinetics","volume":"10","author":"Zakynthinaki","year":"2015","journal-title":"PLoS One"}],"container-title":["Physiological Measurement"],"original-title":[],"link":[{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7","content-type":"text\/html","content-version":"am","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7\/pdf","content-type":"application\/pdf","content-version":"am","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7\/pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7\/pdf","content-type":"application\/pdf","content-version":"am","intended-application":"similarity-checking"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,7,26]],"date-time":"2025-07-26T11:06:47Z","timestamp":1753528007000},"score":1,"resource":{"primary":{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6579\/ad56f7"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,6,1]]},"references-count":46,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2024,6,25]]},"published-print":{"date-parts":[[2024,6,1]]}},"URL":"https:\/\/doi.org\/10.1088\/1361-6579\/ad56f7","relation":{},"ISSN":["0967-3334","1361-6579"],"issn-type":[{"value":"0967-3334","type":"print"},{"value":"1361-6579","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,6,1]]},"assertion":[{"value":"Identifying time-varying dynamics of heart rate and oxygen uptake from single ramp incremental running tests","name":"article_title","label":"Article Title"},{"value":"Physiological Measurement","name":"journal_title","label":"Journal Title"},{"value":"paper","name":"article_type","label":"Article Type"},{"value":"\u00a9 2024 Institute of Physics and Engineering in Medicine. All rights, including for text and data mining, AI training, and similar technologies, are reserved.","name":"copyright_information","label":"Copyright Information"},{"value":"2023-10-24","name":"date_received","label":"Date Received","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2024-06-11","name":"date_accepted","label":"Date Accepted","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2024-06-25","name":"date_epub","label":"Online publication date","group":{"name":"publication_dates","label":"Publication dates"}}]}}