You do a small thing, a short walk, a grocery run, and you pay for it with days flat in bed. You were told to exercise more. That advice was built on the wrong model. Here is what the crash actually is, and what rebuilds capacity.
ME/CFS has been treated for decades as either unexplained or permanent. Neither is accurate. The underlying mechanism is a metabolic collapse with measurable signatures (NK cell deficits, reduced cerebral metabolic rate, tissue-level thyroid resistance) and the same protocol that reverses Long Covid reverses pre-COVID-onset ME/CFS through the same mechanism.
Most chronic fatigue syndrome treatments offered over the last 30 years have not addressed the underlying mechanism. Here is an honest assessment of what does and does not work, and the protocol that targets the actual physiology behind CFS.