Dangers of Exercise

Some of these links refer to ME/CFS as per the IOM which is a broad criteria encompassing many patients who may not have ME as defined by the ICC. For choosing proper research candidates, the IC Primer states on page ii:

“…the ICC [International Consensus Criteria] select patients who exhibit explicit multi-systemic neuropathology, and have a pathological low threshold of physical and mental fatigability in response to exertion.”

ME patients who exceed the safe activity threshold have post-exertional neuroimmune exhaustion (P.E.N.E.) which can lead to serious deterioration.

Graded Exercise Therapy (GET) is contraindicated** in anyone with ME.
**something (such as a symptom or condition) that makes a particular treatment or procedure inadvisable


25% ME Group Stance on Exercise from the 25% ME Group Charity – “We are extremely concerned that some medical/care professionals and sports/exercise specialists are still recommending exercise programmes and/or graded exercise therapy (GET) to people who suffer from ME without even adding very prominent warnings about the harm that exercise can cause to ME sufferers – especially those with severe ME.” (U.K.) – August 2020

LETTER to NICE regarding the removal of GET recommendations for ME patients by the 25% M.E. Group Charity. (U.K.) – August 2020

LETTER from the National Centre for Neuroimmunology and Emerging Diseases (Griffith University) describing the harm GET and CBT can impose on ME patients. Permission received for posting. NOTE: A typo labeling the ICC as the International Case Consensus has been recognized by the authors. (U.K.) – 31 January 2019

Opposition to Graded Exercise Therapy (GET) for ME/CFS from the WorkWell Foundation – a letter for health care providers (U.S.) – 01 May 2018


Back in 1990, Dowsett and Ramsay’s study “Myalgic encephalomyelitis–a persistent enteroviral infection?” had this section on why exercise was harmful for people with ME: (reference numbering has been removed)

Exercise related morbidity in ME

Coxsackie viruses are characteristically myotropic and enteroviral genomic sequences have been detected in muscle biopsies from patients with ME. Exercise related abnormalities of function have been demonstrated by nuclear magnetic resonance [20] and single fibre electro-myography including a failure to coordinate oxidative metabolism with anaerobic glycolysis causing abnormally early intracellular acidosis, consistent with the early fatiguability and the slow recovery from exercise in ME.

Coxsackie viruses can initiate non-cytolytic persistent infection in human cells. Animal models demonstrate similar enteroviral persistence in neurological disease, myopericarditis and the deleterious effect of forced exercise on persistently infected muscles. These studies elucidate the exercise-related morbidity and the chronic relapsing nature of ME.

[From the Conclusions section:]

ME predominantly affects the most socially and economically active section of society. Misinterpretation of this common illness as psychogenic delays the early recognition mandatory for modification of life style which may avoid progression to chronic disability.

In a 1992 interview “Conversation Piece. Interview by P.D. Welsby,” Dr. Elizabeth Dowsett said this about exercise and treatment of ME:

“The medical management of ME differs greatly from that of other comparatively short-lived post infectious debility, such as may follow influenza, in that the patient with ME has a 30% chance of cardiac and other systemic complications and must modify their lifestyle to a reduced capacity for as long as it takes the illness to stablize. Early recognition and sensible advice to avoid mental or physical over-exertion, can do much to avert a prolonged chronic illness.”

Research / Articles

Trial By Error: The 2018 PACE Reanalysis and the SMC’s Expert Appraisals by Tuller. David Tuller exposes the flaws found in the UK PACE trial. Experts call for retraction of this research that falsely claimed graded exercise therapy was beneficial for ME patients. (U.S.) – 13 Jan 2020

Graded exercise therapy does not restore the ability to work in ME/CFS – Rethinking of a Cochrane review by Vink and Vink-Niese (Netherlands & Germany) – 14 Jan 2020

Abnormal blood lactate accumulation during repeated exercise testing in myalgic encephalomyelitis/chronic fatigue syndrome by Lien, Johansen, Haslestad, Bøhn, Melsom, Kardel, and Iversen (Norway) – 03 June 2019

Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome? by Davenport, Lehnen, Stevens, VanNess, Stevens, and Snell (U.S.) – 22 Mar 2019

Dangerous exercise. The detrimental effects of exertion and orthostatic stress in Myalgic Encephalomyelitis and chronic fatigue syndrome by Twisk (Netherlands) – 25 Feb 2017

Elevations of Ventricular Lactate Levels Occur in Both Chronic Fatigue Syndrome and Fibromyalgia by Natelson, Vu, Coplan, Mao, Blate, Krang, Soto, Kapusuz and Shungu (U.S) – 20 Feb 2017

Neural consequences of post-exertion malaise in ME/CFS by Cook, Light, Light, Broderick, Shields, Doughtery, Meyer, VanRiper, Stegner, Elligson and Vernon (U.S.) – 13 Feb 2017

A review on cognitive behavorial therapy (CBT) and graded exercise therapy (GET) in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS): CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients with ME/CFS by Twisk and Maes (U.K. and Thailand) – August 2009

ME and CFS Exercise Intolerance from The Paradigm Change – “A list (in reverse chronological order) of peer-reviewed articles from medical journals on the phenomenon of exercise intolerance in myalgic encephalomyelitis and the broader condition of chronic fatigue syndrome.” (U.S.)

Exercise Intolerance Quotes from The Paradigm Change – “… more than two dozen comments from experts in M.E. on this topic. Except where indicated otherwise, the quotes were supplied directly by the named individuals for this collection (in some cases a few years ago).” (U.S.)

CPET Testing for ME/CFS “From M.E. back to “me”‘ – some articles and videos on exercise testing. (U.S.)

“NOT DECONDITIONING” ARTICLES: Information showing that symptoms are not a result of lack of exercise.

Reduced cardiac volumes in chronic fatigue syndrome associate with plasma volume but not length of disease: a cohort study by Newton, Finkelmeyer, Petrides, Frith, Hodgson, Maclachlan. MacGowan and Blamire
Results: There were no relationships between any MR or volume measurements and length of history, suggesting that deconditioning was unlikely to be the cause of these abnormalities. (U.K.) – 24 June 2016

Voices from the Shadows

Voices from the Shadows – Video one covers the danger of exercise (2018 – 8:49). The second video covers the inappropriateness and inaccuracies of the PACE trial (2019 – 8:59). (U.K.)

Twitter Commentary

by Vlad Vexler (25 Oct 2021 – 1:34) – Vlad (accurately) describes how exercise affects ME patients.