Hi again panda, I was just reading your blog
http://www.diaryofabrokenmind.com/category/cfsme/ and from the fact you were able to do a marathon without severe repercussions and didn't mention you had any delayed PEM (post exertional malaise) with that, I'm thinking there is a very good chance you may be a in a different CFS subgroup then most at this website so peoples experiences may not pertain to you.
"Whether or not someone has a disability, visible or not, including mental and chronic illness, does not in any way mean that they should be judged for doing something, whether that be making a meal on their own or running a god damn marathon!"
Unfortunately you will find yourself judged when it comes to ME/CFS people doing marathons cause it isn't the normal at all. 25% of those who have ME/CFS are housebound/ bedbound not by choice. (I cant leave my home without a support person to push wheelchair, this isn't about who is worst, I'm trying to get across to you just how sick those with this illness usually are and marathons usually far out of the normal equation for this illness).
Generally those who have ME cant do aerobic exercise as we have something wrong physiologically which affects that so we get bad affects from it to the point that it just cant usually be done (there has been studies showing this. There is a list of physiological changes in us based on studies compared to people without this illness in the Canadian consensus ME/CFS overview document).
ME/CFS usually isn't something which can be pushed through (those which do that usually end up paying quite a price) and its this which helps define it more so from what is calling called "chronic fatigue" which also can be severe but just isn't the same thing. Chronic fatigue is all too often confused with ME or ME/CFS but ME has a post exertional worsening of a whole symptom complex (not just fatigue).
The UK what is know as the Wessely school of psychs out to help those with ME/CFS generally deal with those who have "chronic fatigue" . Trudie Chandler is in that boat so if its that you have, she may be right for you.
Whatever you do, I hope you find something which helps you.