{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T09:55:12Z","timestamp":1781517312642,"version":"3.54.1"},"reference-count":26,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2026,6,13]],"date-time":"2026-06-13T00:00:00Z","timestamp":1781308800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Gerald Baum Research Fond\u2014Israeli Lung Association"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: COPD patients often complain of severe dyspnea when walking uphill, even up a mild incline. This study aimed to determine whether the dyspnea experienced during uphill walking is disproportionate to the increased mechanical work required to overcome gravity. Methods: Fourteen COPD patients (FEV1 49 \u00b1 11% predicted) and nine healthy participants performed three symptom-limited exercise tests on a treadmill, each at a fixed grade: 1%, 2.5%, and 4% for COPD patients; and 1%, 3%, and 5% for healthy participants. Treadmill speed was increased stepwise (3 min\/stage). Inspiratory capacity (IC) maneuvers were performed during the last minute of each stage. Borg dyspnea scores (0\u201310) at the different inclines were compared at a uniform level of oxygen uptake (iso-V\u02d9O2). Results: Borg dyspnea scores by COPD patients at the highest iso-V\u02d9O2 attained were significantly higher at 4% treadmill grade compared to 2.5% and compared to 1% grade (7 \u00b1 2 vs. 5 \u00b1 2 vs. 5 \u00b1 2, respectively; p &lt; 0.001 for 4% vs. 1% grade, p &lt; 0.005 for 4% vs. 2.5%). Dynamic hyperinflation worsened with grade, as reflected by decrease in inspiratory reserve volume (IRV) at the highest common iso-V\u02d9O2 attained: 798 \u00b1 336 mL at 1% grade vs. 698 \u00b1 325 mL at 2.5% (p &lt; 0.004) vs. 564 \u00b1 350 mL at 4% (p &lt; 0.002 for 4% vs. 1%; p &lt; 0.004 for 4% vs. 2.5%). In contrast, healthy participants showed no significant grade-dependent differences in dyspnea or IRV at iso-V\u02d9O2. Conclusions: Walking uphill in itself increases breathlessness of COPD subjects at iso-V\u02d9O2, suggesting that the increased dyspnea cannot be explained simply by the increased work. This phenomenon may be related to dynamic hyperinflation, which is worse at steeper inclines.<\/jats:p>","DOI":"10.3390\/jcm15124601","type":"journal-article","created":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T08:57:58Z","timestamp":1781513878000},"page":"4601","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Walking Uphill Aggravates Dyspnea and Dynamic Hyperinflation at Equivalent Oxygen Uptake in COPD Patients"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0810-3680","authenticated-orcid":false,"given":"Ronen","family":"Reuveny","sequence":"first","affiliation":[{"name":"Pulmonary Institute, Sheba Medical Center, Tel-HaShomer, Ramat Gan 5266202, Israel"},{"name":"Physical Therapy Department, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 3103301, Israel"},{"name":"Dina Recanati School of Medicine, Reichman University, Herzliya 4610101, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amit","family":"Yaniv","sequence":"additional","affiliation":[{"name":"Pulmonary Institute, Sheba Medical Center, Tel-HaShomer, Ramat Gan 5266202, Israel"},{"name":"Zinman College of Physical Education and Sport Sciences, Levinsky-Wingate Academic College, Wingate Campus, Netanya 4290200, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4540-4039","authenticated-orcid":false,"given":"Einat","family":"Kodesh","sequence":"additional","affiliation":[{"name":"Physical Therapy Department, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 3103301, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4691-6797","authenticated-orcid":false,"given":"Tal","family":"Krasovsky","sequence":"additional","affiliation":[{"name":"Physical Therapy Department, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 3103301, Israel"},{"name":"Pediatric Rehabilitation Department, The Edmond and Lily Safra Children\u2019s Hospital, Sheba Medical Center, Ramat Gan 5266202, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arie","family":"Rotstein","sequence":"additional","affiliation":[{"name":"Zinman College of Physical Education and Sport Sciences, Levinsky-Wingate Academic College, Wingate Campus, Netanya 4290200, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ariela","family":"Velner","sequence":"additional","affiliation":[{"name":"Pulmonary Institute, Sheba Medical Center, Tel-HaShomer, Ramat Gan 5266202, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5079-4027","authenticated-orcid":false,"given":"Michael J.","family":"Segel","sequence":"additional","affiliation":[{"name":"Pulmonary Institute, Sheba Medical Center, Tel-HaShomer, Ramat Gan 5266202, Israel"},{"name":"Gray Faculty of Medicine, Tel-Aviv University, Tel Aviv 6997801, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,13]]},"reference":[{"key":"ref_1","first-page":"225","article-title":"Dyspnea and activity limitation in COPD: Mechanical factors","volume":"4","author":"Laveneziana","year":"2007","journal-title":"COPD J. 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