{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,21]],"date-time":"2026-06-21T20:48:37Z","timestamp":1782074917047,"version":"3.54.5"},"reference-count":14,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T00:00:00Z","timestamp":1781654400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["High Altitude Medicine & Biology"],"abstract":"\n Kolokas, Iraklis, Jenny Schlichtiger, Sara Jamali, Lina Kronschnabel, Paul Adam, Jeremias G\u00f6tschke, Pontus Mertsch, Christian Goelz, Solveig Vieluf, and Stefan Brunner. Exercise-induced autonomic and cardio-respiratory stress at high altitude in leisure athletes.\n High Alt Med Biol.<\/jats:italic>\n 00:00\u201300, 2026.\n <\/jats:p>\n \n Background:<\/jats:title>\n Exercise at high altitude imposes additional cardiovascular and autonomic demands on leisure athletes. We investigated how acute exposure to high altitude alters cardiovascular, respiratory, and autonomic regulation during rest, exercise start, and peak exercise.<\/jats:p>\n <\/jats:sec>\n \n Methods:<\/jats:title>\n Briefly, 12 nonacclimatized participants (five female) performed standardized exercise tests at low and high altitude, while heart rate (HR), respiratory rate (RR), heart rate variability (HRV_RMSSD), respiratory rate variability (RRV_RMSSD), and respiratory sinus arrhythmia (RSA) were measured using wearable electrocardiogram (ECG) recordings and computer-based signal analysis.<\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n \n Maximal power output during the maximal incremental cycling test was lower at high altitude (235.5 \u00b1 65.5 W) compared to low altitude (276.4 \u00b1 77.5 W). HR and RR increased with exercise intensity and showed a nonsignificant increase at high altitude. RMSSD decreased during exercise (\u2212116.67 \u00b1 79.29 ms,\n p<\/jats:italic>\n < 0.01) and at high altitude (\u221250.16 \u00b1 91.55 ms,\n p<\/jats:italic>\n = 0.015), with a significant interaction during exercise at high altitude (\n p<\/jats:italic>\n < 0.01), while RRV remained relatively stable. RSA was reduced at high altitude (\u22121.1 \u00b1 0.71 bpm,\n p<\/jats:italic>\n = 0.028) and during exercise (\u22124.37 \u00b1 0.38 bpm,\n p<\/jats:italic>\n < 0.01), reflecting lower cardio-respiratory coupling.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion:<\/jats:title>\n These patterns indicate that acute high-altitude exercise shifts autonomic balance, imposing heightened cardiac strain while the respiratory system maintains adaptive ventilatory flexibility, highlighting their differential roles in supporting oxygen delivery and systemic homeostasis under hypoxic stress.<\/jats:p>\n <\/jats:sec>","DOI":"10.1177\/15578682261462332","type":"journal-article","created":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T17:01:26Z","timestamp":1781715686000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Exercise-Induced Autonomic and Cardio-Respiratory Stress at High Altitude in Leisure Athletes"],"prefix":"10.1177","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-6479-7180","authenticated-orcid":false,"given":"Iraklis","family":"Kolokas","sequence":"first","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jenny","family":"Schlichtiger","sequence":"additional","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"Center for Sports Medicine, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Jamali","sequence":"additional","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lina","family":"Kronschnabel","sequence":"additional","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"Center for Sports Medicine, LMU University Hospital, LMU Munich, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul","family":"Adam","sequence":"additional","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"Center for Sports Medicine, LMU University Hospital, LMU Munich, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeremias","family":"G\u00f6tschke","sequence":"additional","affiliation":[{"name":"Department of Medicine V, LMU University Hospital, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), LMU Munich, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pontus","family":"Mertsch","sequence":"additional","affiliation":[{"name":"Department of Medicine V, LMU University Hospital, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), LMU Munich, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christian","family":"Goelz","sequence":"additional","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Solveig","family":"Vieluf","sequence":"additional","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6608-5279","authenticated-orcid":false,"given":"Stefan","family":"Brunner","sequence":"additional","affiliation":[{"name":"Department of Medicine I, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"Center for Sports Medicine, LMU University Hospital, LMU Munich, Munich, Germany."},{"name":"DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,6,17]]},"reference":[{"key":"e_1_3_3_2_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00421-018-3945-5"},{"key":"e_1_3_3_3_1","doi-asserted-by":"publisher","DOI":"10.1111\/sms.13670"},{"key":"e_1_3_3_4_1","doi-asserted-by":"publisher","DOI":"10.1089\/ham.2018.0041"},{"key":"e_1_3_3_5_1","doi-asserted-by":"publisher","DOI":"10.1089\/ham.2020.0131"},{"key":"e_1_3_3_6_1","doi-asserted-by":"publisher","DOI":"10.1080\/10641963.2023.2238923"},{"key":"e_1_3_3_7_1","doi-asserted-by":"publisher","DOI":"10.3389\/fphys.2025.1696346"},{"key":"e_1_3_3_8_1","doi-asserted-by":"publisher","DOI":"10.3758\/s13428-020-01516-y"},{"key":"e_1_3_3_9_1","doi-asserted-by":"publisher","DOI":"10.1093\/eurjpc\/zwaf236.399"},{"key":"e_1_3_3_10_1","doi-asserted-by":"publisher","DOI":"10.1089\/ham.2016.0112"},{"key":"e_1_3_3_11_1","doi-asserted-by":"crossref","unstructured":"Seabold S Perktold J. (2010). Statsmodels: Econometric and Statistical Modeling with Python. In: Proceedings of the 9th Python in Science Conference (SciPy 2010).","DOI":"10.25080\/Majora-92bf1922-011"},{"key":"e_1_3_3_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.mjafi.2021.07.002"},{"key":"e_1_3_3_13_1","doi-asserted-by":"publisher","DOI":"10.1097\/MD.0000000000042692"},{"key":"e_1_3_3_14_1","doi-asserted-by":"publisher","DOI":"10.1109\/JBHI.2024.3456028"},{"key":"e_1_3_3_15_1","doi-asserted-by":"publisher","DOI":"10.1113\/JP281724"}],"container-title":["High Altitude Medicine & Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/15578682261462332","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/15578682261462332","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/15578682261462332","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,21]],"date-time":"2026-06-21T20:18:08Z","timestamp":1782073088000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/15578682261462332"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,17]]},"references-count":14,"alternative-id":["10.1177\/15578682261462332"],"URL":"https:\/\/doi.org\/10.1177\/15578682261462332","relation":{},"ISSN":["1527-0297","1557-8682"],"issn-type":[{"value":"1527-0297","type":"print"},{"value":"1557-8682","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,17]]},"article-number":"15578682261462332"}}