I have come across anecdotal mention of this symptom but never seen it included in any diagnostic criteria I can remember. It is something that I regularly experience a lot, particularly as part of PEM. At the very beginning, I struggled to push the duvet off me in bed. Nowadays, it is a sure sign that I am overdoing it as everything becomes much heavier. My whole body, particularly my legs; anything I try to lift feels as if it's quadrupled in weight. It's as though someone has increased gravity. I'm 5'6 and weigh 8stone but at times it's like I'm more than twice that. Just wondered how common it was and what reason there might be for it?