Wackers,
I've mentioned this very thing to my doctor at least twice - questioning why on Earth does physical exertion lead to feeling sick! - and he says, "Yeah, this happens with Fibro and we don't know why." So, because I really trust him, I don't worry much about
it anymore. It's just part of the package. Still a pain in the behind, of course, but I figure: so it goes...and it always does (go, I mean - eventually.)
But I feel like I always have to live "life lite," walking on eggshells, never letting myself fully get into anything for any length of time. It just sucks! I also think this contributes to fog, because switching activities (and muscle groups) so often leads to fragmented thinking...that's my theory, anyway.
Hope you feel better soon!
Debbie