Deviant cellular and physiological responses to exercise in Myalgic Encephalomyelitis and chronic fatigue syndrome

Post-exertional "malaise" is a hallmark symptom of Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS). Various abnormalities, including abnormal physiological responses to exertion, can account for post-exertional "malaise� and "exercise avoidance". Since these abnormalities are not observed in sedentary healthy controls, the abnormalities and deviant responses cannot be explained by "exercise avoidance" and subsequent deconditioning, nor by psychogenic factors.