Did you ever try that stimulator when you were past the point of "I'm out of energy"? I think that's an interesting test of the "limited ATP" hypothesis for that symptom.
i am not doing that test!
do you know how atp regeneration works? it cycles between ATP and ADP , this works pretty fast. but if you push over the body needs to kick off the 2nd phosphate group from ADP where it gets to AMP , this happens if you overexercise or push over the limits to exhaustion.
if this happens, the body needs to regenerate ATP from the ground up via de novo synthesis, which takes approx 48 hours in healthy people.
and us sick folx might be fucked up here, so the denovo will never get back to normal. i can only warn against any cfs sufferer from trying to do anything when the body is already out of energy.