Berardi, Giovanni, Janowski, Adam, McNally, Samuel et al. · Medicine and science in sports and exercise · 2026 · DOI
This study looked at what happens when people with ME/CFS or long COVID do moderate exercise. Researchers asked 60 patients and 30 healthy people to exercise for 25 minutes, then tracked their symptoms for a week. Most patients with ME/CFS experienced worsening fatigue, mental fog, and other symptoms in the days after exercise, but the severity and which symptoms got worse varied from person to person.
Understanding PESE variability is crucial for tailoring exercise recommendations in ME/CFS and long COVID. This study provides evidence that symptom response to exercise is heterogeneous, suggesting that one-size-fits-all exercise prescriptions may not be appropriate and that careful individual assessment is necessary to avoid harm.
This study does not establish whether submaximal exercise is universally safe or harmful for ME/CFS patients—only that responses vary significantly. It does not identify which biological mechanisms cause PESE or predict which individual patients will experience severe exacerbations. The 7-day timeframe may not capture delayed or prolonged exacerbations lasting weeks or longer.
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
Berardi, Giovanni, Janowski, Adam, McNally, Samuel, Post, Andrew, Garg, Alpana, & Sluka, Kathleen A (2026). Postexertional Symptom Exacerbation after Submaximal Exercise in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Postacute Sequelae of COVID-19.. Medicine and science in sports and exercise. https://doi.org/10.1249/MSS.0000000000003891
BibTeX
@article{mecfsatlas-berardi-2026-postexertional-symptom,
author = {Berardi, Giovanni and Janowski, Adam and McNally, Samuel and Post, Andrew and Garg, Alpana and Sluka, Kathleen A},
title = {Postexertional Symptom Exacerbation after Submaximal Exercise in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Postacute Sequelae of COVID-19.},
journal = {Medicine and science in sports and exercise},
year = {2026},
doi = {10.1249/MSS.0000000000003891},
note = {PubMed: 41185151},
url = {https://www.mecfsatlas.com/evidence/berardi-2026-postexertional-symptom},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/berardi-2026-postexertional-symptom
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