Franklin, John Derek, Atkinson, Greg, Atkinson, Janet M et al. · International journal of sports medicine · 2019 · DOI
This research review analyzed 32 studies comparing how much oxygen people with ME/CFS can use during maximum exercise compared to healthy people. On average, people with ME/CFS used about 5 milliliters less oxygen per kilogram of body weight per minute than healthy controls—a meaningful difference that likely affects real-world functioning. This reduced oxygen capacity is one of the measurable physical differences between ME/CFS patients and healthy individuals.
Reduced oxygen uptake capacity is an objective, measurable physiological marker that validates ME/CFS as a real medical condition with demonstrable physical impairment. This finding supports the use of cardiopulmonary exercise testing in clinical assessment and helps quantify the severity of functional limitation patients experience. Understanding this biological abnormality may guide rehabilitation approaches and help distinguish ME/CFS from other conditions.
This meta-analysis does not establish the cause of reduced VO₂peak—whether it results from cardiac dysfunction, mitochondrial impairment, muscle pathology, or another mechanism remains unclear. The study is correlational and cannot prove that low oxygen uptake causes fatigue or other ME/CFS symptoms. It also does not address whether VO₂peak changes over time or whether specific treatments can improve this measure.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Franklin, John Derek, Atkinson, Greg, Atkinson, Janet M, & Batterham, Alan M (2019). Peak Oxygen Uptake in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Meta-Analysis.. International journal of sports medicine. https://doi.org/10.1055/a-0802-9175
BibTeX
@article{mecfsatlas-franklin-2019-peak-oxygen,
author = {Franklin, John Derek and Atkinson, Greg and Atkinson, Janet M and Batterham, Alan M},
title = {Peak Oxygen Uptake in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Meta-Analysis.},
journal = {International journal of sports medicine},
year = {2019},
doi = {10.1055/a-0802-9175},
note = {PubMed: 30557887},
url = {https://www.mecfsatlas.com/evidence/franklin-2019-peak-oxygen},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/franklin-2019-peak-oxygen
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