Looking at the ME Association Survey on CBT, GET and pacing in more detail, it does on the face of it seem to provide evidence of a negative effect of GET in 68% of mild to moderate ME/CFS patients, and in 87% of the severe ME/CFS patients (page 208 of
the survey). As well of course as evidence for a positive effect of GET in a small percentage of patients.
Interesting that in the mild to moderate group, 4% of patients found they either became completely well or very much better after GET. That does tie in with the reports we sometimes see on this forum or in newspapers that exercise cured or greatly improved some ME/CFS patients.
What I would like to know, in both the negative and positive effects cases, is how long these effects lasted after the course of GET was finished. Were these good and bad effects just a temporary condition, that lasted say three to six months, or were they much more long lasting or permanent?
Whether the results of GET were permanent or temporary makes a big difference in interpreting them. If these results were only relatively temporary for a few months, then we cannot say that GET either permanently harms or permanently improves ME/CFS.
It is a pity that the survey did not include a question asking patients how long the good/bad effects lasted for.
Another question that I would have liked to seen in the survey is one about the early signs and early warnings about positive and negative effects of GET, as the course of GET was started and progressed. It would have been good to know whether those patients who significantly benefited from GET started to feel these benefits early on in the GET treatment; and likewise, whether those who had significant negative effects from GET started to notice these ill effects at an early stage.
Assuming there were these easy-to-spot early indications of good or bad effects, then the advice that should be given to ME/CFS patients regarding exercise would be that if it feels it is doing you good, then continue with your exercise program; whereas if it feels like it is having a negative effect, then stop you exercise program.
That would very much simplify and clarify the advice that we can give on this forum regarding exercise.