File:ExerciseinCFS1.jpg

Exercise (thirty minutes cycling) reduces symptoms in healthy people (blue) but massively increases them in ME/CFS patients (red) - causing post-exertional malaise.

Summary
Effects of exercise in patients with chronic fatigue syndrome.

Fig. 1. Total symptom changes for ME/CFS and control pre- to 24-h post-exercise. Total symptoms are based on the sum of 10 VAS ratings derived from 10 items contained in the CDC symptom inventory.

Citation:
Brain, Behavior, and Immunity Volume 62, May 2017, Pages 87-99 Neural consequences of post-exertion malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Authors: Dane B. Cook, Alan R. Light, Kathleen C. Light, Gordon Broderick, Morgan R. Shields, Ryan J. Dougherty, Jacob D.Meyer, Stephanie Van Riper, Aaron J. Stegner, Laura D. Ellingsone, Suzanne D. Vernon https://www.sciencedirect.com/science/article/pii/S088915911730051X