CFS for a few minutes, harder than running marathon!

There's medical data to back up that claim too. Here's an interesting look at one researcher's theories about pain and fatigue processing. When you scroll half way through the article you will see two different sets of charts showing the difference between healthy people and those with Chronic Fatigue Syndrome, including the clinical results for pain and sympathetic nervous system reactors after 15 minutes of mild exercise by CFS patients and the same receptors in a healthy person after a 26-mile marathon.
Adrenergic and Sensory Receptor Expression on Leukocytes Increases After Moderate Exercise in Chronic Fatigue And Fibromyalgia.

The activity of a receptor called Type A that’s been implicated in pain doubled in ME/CFS patients who also had FM and showed no increase in healthy subjects at all. Sympathetic nervous system (adrenergic) receptors that detect SNS activity were increased 2-6 times.

How active are these receptors? These sensors, not surprisingly, get really active in marathon runners but they still never got as active in marathoners (after a 26-mile run ) as they did in ME/CFS/FM patients (after a mild 15-minute exercise period).