{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T01:05:45Z","timestamp":1791335145402,"version":"4.3.1"},"reference-count":68,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T00:00:00Z","timestamp":1777248000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T00:00:00Z","timestamp":1777248000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Johannes Gutenberg-Universit\u00e4t Mainz"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sports Med - Open"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Patients severely affected by post-COVID-19 condition (PCC) and myalgic encephalomyelitis\/chronic fatigue syndrome (ME\/CFS) often experience long-term work incapacity, contributing to a growing economic burden. Organ-centered clinical diagnostics frequently fail to explain their work disability.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>\n                      We aimed to objectively assess physical work ability using cardiopulmonary exercise testing (CPET) in a cohort of long-standing and severely affected PCC patients. We hypothesized: (1) patients with ME\/CFS exhibit lower peak oxygen uptake (VO\u2082\n                      <jats:sub>peak<\/jats:sub>\n                      [mL\/min\/kg]) and peak power output (PPO [W\/kg]) than those without; (2) most patients demonstrate objective work disability, closely aligned with subjective perception of disability; (3) oxygen pulse (O\n                      <jats:sub>2<\/jats:sub>\n                      pulse [mL\/bpm]) is reduced in ME\/CFS, independent of comorbidity.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>The study was conducted in the Department of Sports Medicine, Prevention and Rehabilitation at Johannes Gutenberg-University Mainz (Mainz, Germany). Between July 31, 2023, and March 31, 2025, a total of 92 PCC patients with suspected occupational disease underwent symptom-limited CPET and completed the Canadian Consensus Criteria, Bell Disability Scale (Bell-Score), and DePaul Symptom Questionnaire (Post-Exertional Malaise) Short Form (DSQ-PEM).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Nearly half of the patients (49%) met ME\/CFS criteria and 79% screened positive on the DSQ-PEM. ME\/CFS patients showed significantly lower VO\u2082\n                      <jats:sub>peak<\/jats:sub>\n                      (13.0\u2009\u00b1\u20093.1 vs. 15.4\u2009\u00b1\u20094.9, p\u2009=\u20090.012), PPO (0.9\u2009\u00b1\u20090.3 vs. 1.1\u2009\u00b1\u20090.5, p\u2009=\u20090.014), and O\u2082 pulse (7.7\u2009\u00b1\u20092.0 vs. 8.5\u2009\u00b1\u20091.9, p\u2009=\u20090.047) compared to those without ME\/CFS. Overall, 66% of patients met objective thresholds for work disability (VO\u2082\n                      <jats:sub>peak<\/jats:sub>\n                      \u2009&lt;\u200915\u00a0mL\/min\/kg or PPO\u2009&lt;\u20091 W\/kg). Forty-five patients (51%) had a Bell-Score\u2009\u2264\u200930 and 82% from those had VO\u2082\n                      <jats:sub>peak<\/jats:sub>\n                      \u2009&lt;\u200915\u202fand\/or PPO\u2009&lt;\u20091. VO\u2082\n                      <jats:sub>peak<\/jats:sub>\n                      and PPO significantly correlated with Bell-Score (r\u2009=\u20090.3, p\u2009=\u20090.005 and r\u2009=\u20090.3, p\u2009=\u20090.003) and were the lowest among patients on medical sick leave (13.3\u2009\u00b1\u20093.3 and 0.9\u2009\u00b1\u20090.3), compared to those in occupational reintegration (16.0\u2009\u00b1\u20093.9, p\u2009=\u20090.04 and 1.2\u2009\u00b1\u20090.5, p\u2009=\u20090.024) or currently working (18.0\u2009\u00b1\u20097.1, p\u2009=\u20090.036 and 1.2\u2009\u00b1\u20090.5, p\u2009=\u20090.015).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>\n                      Severely affected PCC patients exhibit objective work disability, particularly those with ME\/CFS. VO\u2082\n                      <jats:sub>peak<\/jats:sub>\n                      and PPO are associated with subjective disability and occupational status. Therefore, early integration of CPET into clinical and occupational evaluations can inform individualized therapy planning and return-to-work decisions.\n                    <\/jats:p>\n                    <jats:p>\n                      <jats:italic>Trial registration<\/jats:italic>\n                      DRKS, DRKS00032394. Registered 28 July 2023,\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"https:\/\/drks.de\/search\/de\/trial\/DRKS00032394\" ext-link-type=\"uri\">https:\/\/drks.de\/search\/de\/trial\/DRKS00032394<\/jats:ext-link>\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s40798-026-00995-1","type":"journal-article","created":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T11:19:14Z","timestamp":1777288754000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME\/CFS Patients"],"prefix":"10.1186","volume":"12","clinical-trial-number":[{"clinical-trial-number":"drks00032394","registry":"10.18810\/drks"}],"author":[{"given":"Aleksandar","family":"Tomaskovic","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vincent","family":"Weber","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David T.","family":"Ochmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Barlo","family":"Hillen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elmo W. 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