Twomey, Rosie, Yeung, Samuel T, Wrightson, James G et al. · Journal of pain and symptom management · 2020 · DOI
This study looked at whether people with long-lasting cancer-related fatigue experience post-exertional malaise (PEM)—a condition where symptoms get worse after physical or mental activity. Researchers asked 18 people with severe, ongoing fatigue to report their experiences over six months and during exercise testing. They found that up to one-third of participants showed signs of PEM, including fatigue that worsened after minimal effort and recovery taking more than 24 hours.
This study is significant because it provides evidence that post-exertional malaise—a hallmark feature of ME/CFS—may also affect people with chronic cancer-related fatigue, suggesting overlapping pathophysiological mechanisms. Recognition of PEM in cancer survivors could prevent harmful exercise prescriptions and inform better management strategies. The findings highlight the importance of screening for PEM across different fatigue conditions and tailoring rehabilitation approaches accordingly.
This study does not establish that cancer-related fatigue and ME/CFS are the same condition, only that some symptom overlap may exist. The small sample size (n=18) and lack of a control group (healthy controls or ME/CFS comparison group) limit generalizability and prevent definitive conclusions about PEM prevalence or severity. Correlation between exercise and symptom worsening does not establish the underlying biological mechanisms causing PEM.
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
Twomey, Rosie, Yeung, Samuel T, Wrightson, James G, Millet, Guillaume Y, & Culos-Reed, S Nicole (2020). Post-exertional Malaise in People With Chronic Cancer-Related Fatigue.. Journal of pain and symptom management. https://doi.org/10.1016/j.jpainsymman.2020.02.012
BibTeX
@article{mecfsatlas-twomey-2020-post-exertional,
author = {Twomey, Rosie and Yeung, Samuel T and Wrightson, James G and Millet, Guillaume Y and Culos-Reed, S Nicole},
title = {Post-exertional Malaise in People With Chronic Cancer-Related Fatigue.},
journal = {Journal of pain and symptom management},
year = {2020},
doi = {10.1016/j.jpainsymman.2020.02.012},
note = {PubMed: 32105793},
url = {https://www.mecfsatlas.com/evidence/twomey-2020-post-exertional},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/twomey-2020-post-exertional
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