OK, so first off I will caveat this by appreciating that it sounds like utter madness considering the classic nature of ME/CFS, PEM and all that, and I would also point out that I'd consider myself mild to moderate having never been truly incapacitated over the two years I've been down with this after suffering a bout of gastroenteritis. With that out of the way then, my experience might be of interest to some on the forum. I've never approached my illness in a sciencey way what with protocols and complex technical assessments although I am firmly an advocate of evidence based medicine. What I have tried are the usual things like taking B12 supplements, probiotics, CBD oil, rohdoila (yeah, probably quackery but my mum sent it), high protein/low carb dieting and a few other things but generally to little benefit although occasionally some seemed to help for while. After a long period of grimness I was getting a bit desperate and decided that I would try the 15 mins a week HIIT method (as seen on Michael Mosely's BBC show). I suspected it may well do me in but since I've got no work on at the minute I figured I didn't have much to lose so thought what the melon-farming hell. The training involves doing 1 minute of any flat out exercise that will get your heart pumping, then repeated 4 more times with a 1min rest period between each exercise. Now, you're probably thinking, oh friendlycat, this is just crazy talk but hear me out. Due to weak, wobbly legs, the best I could manage on the first attempt was kind of kung fu punching and which floored me for the rest of the day, plus I only did a total of three minutes. The next day, however, I really didn't feel too bad and the following day, I did it again for 3 minutes total which did leave me knackered but I recovered after a while the same day. So, it's now been three weeks and I feel pretty much back to normal, i.e. things like going up and down stairs doesn't seem like a big effort, and am doing the full 5 mins during each session which I perform every other day. I'm now doing running on the spot and squats along with the punchy thing. At the moment, I'm really pleased I tried this although I'm aware that it may well be a chimera and the ME will find a way to stymie my progress, but, I've had three weeks of feeling pretty damn good all things considered and for now, I'll take what I can get.