ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

681–700 of 746 studies

E3 PreliminaryMechanismPEM unclearObservational

Severity of symptom flare after moderate exercise is linked to cytokine activity in chronic fatigue syndrome.

White, Andrea T, Light, Alan R, Hughen, Ronald W et al.·Psychophysiology·2010

This study looked at why some people with ME/CFS feel much worse after exercise. Researchers measured immune chemicals in the blood before and after moderate exercise in people with ME/CFS and healthy controls. They found that patients who experienced severe symptom flare had increased levels of certain immune chemicals 8 hours after exercise, while those with mild flare or healthy people did not show this pattern.

Immune SystemPost-Exertional Malaise

E3 PreliminaryReviewPEM requiredReview-Narrative

Chronic fatigue syndrome: Harvey and Wessely's (bio)psychosocial model versus a bio(psychosocial) model based on inflammatory and oxidative and nitrosative stress pathways.

Maes, Michael, Twisk, Frank N M·BMC medicine·2010

This study compares two different ways of understanding ME/CFS. One model suggests the illness is mainly caused by how the mind and behavior interact with the body, and proposes treatments like cognitive behavioral therapy and graded exercise. The other model focuses on biological problems like inflammation and oxidative stress in the body. The authors argue that the biological model better explains ME/CFS and that exercise-based treatments could actually make some patients worse.

Immune SystemPost-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

A new hypothesis of chronic fatigue syndrome: co-conditioning theory.

Tanaka, Masaaki, Watanabe, Yasuyoshi·Medical hypotheses·2010

This article proposes a new theory about how ME/CFS might develop: repeated overwork or stress could train your body and brain to respond with fatigue and an urge to rest, similar to how habits form. The authors suggest that once this pattern becomes established, your body may continue producing fatigue even when you're no longer overworking. This theory could eventually lead to new ways of treating ME/CFS.

Post-Exertional Malaise

E3 PreliminaryCommentaryPEM unclearEditorial

Perspectives on fatigue from the study of chronic fatigue syndrome and related conditions.

Clauw, Daniel J·PM & R : the journal of injury, function, and rehabilitation·2010

This article explains that ME/CFS is a complex illness with roots in both the body and brain, involving several connected problems at the same time. Researchers have found that ME/CFS shares similar patterns with other conditions like fibromyalgia and irritable bowel syndrome, and involves issues with sleep, pain, cognitive problems, and extreme tiredness after activity. The article describes how inflammation, infection, problems with stress hormones, and nerve signal problems may all contribute to ME/CFS, though we don't yet know which problems matter most.

NeuroinflammationPost-Exertional Malaise

E3 PreliminaryMechanismPEM unclearMechanistic

Patients with chronic fatigue syndrome performed worse than controls in a controlled repeated exercise study despite a normal oxidative phosphorylation capacity.

Vermeulen, Ruud C W, Kurk, Ruud M, Visser, Frans C et al.·Journal of translational medicine·2010

This study compared how well people with ME/CFS and healthy controls performed during two exercise tests done 24 hours apart. Patients became exhausted at much lower exercise levels than controls, and performed even worse on the second test. Surprisingly, when researchers tested the energy-producing structures (mitochondria) in patients' blood cells, they appeared to work normally, suggesting the problem may lie elsewhere in the energy production process.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM requiredMechanistic

Pain inhibition and postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: an experimental study.

Van Oosterwijck, J, Nijs, J, Meeus, M et al.·Journal of internal medicine·2010

This study compared how the body's pain-relief systems work in people with ME/CFS versus healthy people during exercise. Researchers found that after exercise, people with ME/CFS became more sensitive to pain (their pain thresholds decreased), while healthy people became less sensitive to pain. The ME/CFS group also experienced worsening symptoms after both types of exercise they tried.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM unclearMechanistic

Moderate exercise increases expression for sensory, adrenergic, and immune genes in chronic fatigue syndrome patients but not in normal subjects.

Light, Alan R, White, Andrea T, Hughen, Ronald W et al.·The journal of pain·2009

This study examined blood cells from ME/CFS patients and healthy people before and after moderate exercise. Researchers found that ME/CFS patients showed much larger changes in genes related to pain sensation, stress response, and immune function after exercise compared to healthy controls. These gene changes lasted from 30 minutes to 2 days and correlated with patients' fatigue and pain symptoms.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM requiredMechanistic

Transcriptional control of complement activation in an exercise model of chronic fatigue syndrome.

Sorensen, Bristol, Jones, James F, Vernon, Suzanne D et al.·Molecular medicine (Cambridge, Mass.)·2009

After exercise, people with ME/CFS show higher levels of certain immune molecules (particularly C4a) that may contribute to their post-exercise symptoms. This study looked at which genes were turned on or off in immune cells after exercise and found that people with ME/CFS activated different immune pathways than healthy people—specifically, a pathway called the lectin pathway responded differently. This suggests their immune system may be producing excess inflammatory signals after physical activity.

Immune SystemPost-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Does hypothalamic-pituitary-adrenal axis hypofunction in chronic fatigue syndrome reflect a 'crash' in the stress system?

Van Houdenhove, Boudewijn, Van Den Eede, Filip, Luyten, Patrick·Medical hypotheses·2009

This study explores why many ME/CFS patients have problems with their stress hormone system, particularly a gland in the brain called the hypothalamus. The researchers suggest that ME/CFS might involve a breakdown in how the body normally responds to stress, leading to an imbalance that triggers excessive inflammation and sickness symptoms like exhaustion and pain sensitivity.

Post-Exertional Malaise

E3 PreliminaryGuidelinePEM not requiredGuideline

Chronic fatigue syndrome: aetiology, diagnosis and treatment.

Avellaneda Fernández, Alfredo, Pérez Martín, Alvaro, Izquierdo Martínez, Maravillas et al.·BMC psychiatry·2009

ME/CFS is a serious condition marked by extreme exhaustion that lasts at least six months and doesn't improve with rest. The fatigue is so severe that it can force people to reduce their daily activities by half or more. Doctors don't yet have a single test to diagnose it, so they diagnose it by ruling out other illnesses. There is currently no cure, but treatment works best when doctors, mental health professionals, and social support services work together to help patients.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM unclearCross-Sectional

Seven genomic subtypes of chronic fatigue syndrome/myalgic encephalomyelitis: a detailed analysis of gene networks and clinical phenotypes.

Kerr, J R, Burke, B, Petty, R et al.·Journal of clinical pathology·2008

This study found that ME/CFS is not a single disease but actually seven different types, each with its own genetic fingerprint and specific symptoms. Researchers looked at blood samples and identified which genes were turned on or off differently in patients compared to healthy people, and then grouped patients based on these genetic patterns. Each genetic subtype had different combinations of symptoms—some people struggled mainly with brain fog, others with pain and muscle problems, and some with multiple severe issues affecting sleep, mood, and digestion.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM unclearMechanistic

Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls.

Thambirajah, Anita A, Sleigh, Kenna, Stiver, H Grant et al.·Clinical and investigative medicine. Medecine clinique et experimentale·2008

This study looked at special protective proteins called heat shock proteins (HSPs) in the blood cells of ME/CFS patients and healthy people before and after exercise. The researchers found that ME/CFS patients had higher levels of these proteins at rest, but their levels dropped after exercise and stayed low for a week. In contrast, healthy people's HSP levels stayed stable or increased after exercise. This difference suggests ME/CFS patients may have trouble recovering from physical stress.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Pilot study of peripheral muscle function in primary biliary cirrhosis: potential implications for fatigue pathogenesis.

Hollingsworth, Kieren G, Newton, Julia L, Taylor, Roy et al.·Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association·2008

This study examined how muscles produce and use energy in patients with primary biliary cirrhosis (PBC), a liver disease where the immune system attacks mitochondria—the energy factories inside cells. Using a special MRI technique, researchers measured how quickly muscles recovered after exercise and found that PBC patients had problems with this energy recovery process. The study also included people with ME/CFS and found that how quickly muscles can clear acid buildup after exercise may determine whether patients feel severely fatigued.

Post-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Chronic fatigue syndrome: characteristics and possible causes for its pathogenesis.

Bassi, Nicola, Amital, Daniela, Amital, Howard et al.·The Israel Medical Association journal : IMAJ·2008

This review examines multiple biological abnormalities that might explain ME/CFS symptoms. Researchers found evidence that the immune system may not work properly in ME/CFS patients, with potential problems in natural killer cells, antibody levels, and inflammatory markers. The study also suggests that certain autoantibodies and problems with chemical messengers in the nervous system might contribute to fatigue, brain fog, and muscle pain.

Immune SystemPost-Exertional Malaise

E3 PreliminaryBehavioralPEM not requiredObservational

Open-label study of s-citalopram therapy of chronic fatigue syndrome and co-morbid major depressive disorder.

Amsterdam, Jay D, Shults, Justine, Rutherford, Nancy·Progress in neuro-psychopharmacology & biological psychiatry·2008

This study tested whether an antidepressant medication called s-citalopram could help people with ME/CFS who also had depression. Sixteen patients took the medication for up to 12 weeks, and researchers measured changes in fatigue, pain, sleep, and mood using standard questionnaires. The results showed improvements in fatigue severity, several ME/CFS symptoms, and depression scores during treatment.

Post-Exertional Malaise

E3 PreliminaryPEM unclear

Can exercise limits prevent post-exertional malaise in chronic fatigue syndrome? An uncontrolled clinical trial.

Nijs, Jo, Almond, Freya, De Becker, Pascale et al.·Clinical rehabilitation·2008

This study tested whether limiting both how hard and how long people with ME/CFS exercise could prevent post-exertional malaise (feeling much worse after activity). Twenty-four patients did a controlled walking test designed to stay within their personal limits. While tiredness improved within 24 hours, pain increased and didn't fully go away, and some patients reported their overall health got worse. The exercise limits helped prevent major health changes but didn't completely stop symptom flare-ups.

Post-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Rehabilitation of decreased motor performance in patients with chronic fatigue syndrome: should we treat low effort capacity or reduced effort tolerance?

Van Houdenhove, B, Verheyen, L, Pardaens, K et al.·Clinical rehabilitation·2007

This paper proposes a new way to think about why people with ME/CFS have reduced physical ability. The authors suggest there may be two different problems: some patients may have low energy capacity (their bodies can't produce enough energy), while others may have reduced effort tolerance (their nervous system tells them to stop before their body actually reaches its limit). Understanding which problem a patient has could help doctors choose better treatments.

Post-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

[Cirrhotic cardiomyopathy].

Osipenko, M F, Bikbulatova, E A·Klinicheskaia meditsina·2007

This review examines how liver cirrhosis (severe liver disease) affects the heart. The study found that patients with cirrhosis develop heart problems including thickened heart walls and weakened heart function, especially during physical activity. These heart changes may contribute to fatigue and reduced ability to work, but importantly, these problems can improve significantly after a liver transplant.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredMechanistic

Sense of effort during a fatiguing exercise protocol in chronic fatigue syndrome.

Wallman, Karen E, Sacco, Paul·Research in sports medicine (Print)·2007

This study asked whether people with ME/CFS feel more effort when doing physical tasks compared to healthy people. Researchers had both groups perform a repetitive arm exercise for 45 minutes while rating how hard it felt. People with ME/CFS reported significantly higher effort levels and produced more force than controls, even though the task was the same for everyone.

Post-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

[Chronic fatigue syndrome--exercise and physical activity].

Greenberg, Shai, Frid, Mordechai·Harefuah·2006

People with ME/CFS often feel extremely tired and struggle with physical activity, experiencing worsening symptoms even after light exercise. This review found that ME/CFS patients typically have lower fitness levels, their hearts work harder during normal activity, and they take longer to recover than healthy people. The good news is that carefully guided exercise programs appear to be the most helpful treatment for improving energy levels, physical function, and daily life activities.

Post-Exertional Malaise

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

Severity of symptom flare after moderate exercise is linked to cytokine activity in chronic fatigue syndrome.

Chronic fatigue syndrome: Harvey and Wessely's (bio)psychosocial model versus a bio(psychosocial) model based on inflammatory and oxidative and nitrosative stress pathways.

A new hypothesis of chronic fatigue syndrome: co-conditioning theory.

Perspectives on fatigue from the study of chronic fatigue syndrome and related conditions.

Patients with chronic fatigue syndrome performed worse than controls in a controlled repeated exercise study despite a normal oxidative phosphorylation capacity.

Pain inhibition and postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: an experimental study.

Moderate exercise increases expression for sensory, adrenergic, and immune genes in chronic fatigue syndrome patients but not in normal subjects.

Transcriptional control of complement activation in an exercise model of chronic fatigue syndrome.

Does hypothalamic-pituitary-adrenal axis hypofunction in chronic fatigue syndrome reflect a 'crash' in the stress system?

Chronic fatigue syndrome: aetiology, diagnosis and treatment.

Seven genomic subtypes of chronic fatigue syndrome/myalgic encephalomyelitis: a detailed analysis of gene networks and clinical phenotypes.

Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls.

Pilot study of peripheral muscle function in primary biliary cirrhosis: potential implications for fatigue pathogenesis.

Chronic fatigue syndrome: characteristics and possible causes for its pathogenesis.

Open-label study of s-citalopram therapy of chronic fatigue syndrome and co-morbid major depressive disorder.

Can exercise limits prevent post-exertional malaise in chronic fatigue syndrome? An uncontrolled clinical trial.

Rehabilitation of decreased motor performance in patients with chronic fatigue syndrome: should we treat low effort capacity or reduced effort tolerance?

[Cirrhotic cardiomyopathy].

Sense of effort during a fatiguing exercise protocol in chronic fatigue syndrome.

[Chronic fatigue syndrome--exercise and physical activity].

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research