According to leading CFS physician Paul Cheney, M.D., “Golden Rule: Find the boundaries of what you can do and then stay within them. Both trying to do too much, or pulling back and doing too little are counter productive.
Limit setting is probably the most important thing you can do. Patients are very susceptible to push-crash phenomena and you need to learn to stay within certain boundaries. To the extent you do that, you will tend to do better. To the extent you don’t, you likely will not do well. Aerobic Training: Beyond certain limits this cannot be attempted until you are much improved. Be cautious about any aerobic exercise (any sustained activity, such as running, walking, or swimming, designed to raise the heart rate and increase oxygen flow throughout the body).
The aerobic system is injured and reactive oxygen species (free radicals) generated in the mitochondria by excessive training may not be detoxified with resulting injury which can potentially be permanent (DNA damage). Walk, cycle or swim only as much as your body will allow, no more than 20 minutes, three times per week. Aerobic exercise past a certain point can dramatically worsen this disorder.”
(Source: Dr. Cheney’s Basic Treatment Plan for Chronic Fatigue Syndrome. ImmuneSupport.com)