I'm glad you brought this up! There is a researcher/professor at Stanford named Sean Mackey. I listened to him give a lecture on Fibromyalgia and Chronic pain on the Research Channel on TV. Actually I've seen it twice. I found a link to this show online so you can watch it if you'd like. I listen to it now and then and always gain some information from it.
But the reason I'm bringing this up is that he talks about
the 'runners high'...or lack of in people with fibromyalgia. Where "normal" people will get that high, people with fibro never feel it. We get tired and miserable. Being outside and walking, modest exercise can help us physically and mentally but we lack something in the brain that prevents that high.
If you'd like to watch this lecture here's the link. I do think it's well worth your time. I think I'll start a thread for this video...
Chutz
the video:
www.researchchannel.org/prog/displayevent.aspx?fid=345&rid=28078this page has links to many of his lectures on chronic pain and the research they are doing at the Stanford Pain Clinic:
video.google.com/videosearch?hl=en&client=firefox-a&rlz=1R1GGIC_en___US356&hs=hER&resnum=0&q=sean+mackey&um=1&ie=UTF-8&ei=blFyS4zKJoXgtgPFyNXOAQ&sa=X&oi=video_result_group&ct=title&resnum=4&ved=0CBoQqwQwAw#