I'd like to comment on the first sentence of the last paragraph in the conclusions section. If GET can correct low blood volume (I did not explore the mechanisms cited in the paper cited by Hollingsworth et al. - vascular tone?), it is my personal belief that it does not directly address the problem and that based upon numerous accounts and personal experience, desmopressin is more direct and exceedingly effective in severe cases. It is likely that these same severe cases are also the patients most susceptible to the negative impact of too much activity (perhaps in the form of neural dysfunction/damage - a mechanism that has been proposed as the possible underlying cause of DI in some cases of ME). I will be cross-posting this to thread on the Klimas exercise videos. ETA - I just checked the article cited by Hollingsworth et al. There is no reference in that article to a relationship between GET and hypovolemia (Can pacing self-management alter physical behavior and symptom severity in chronic fatigue syndrome? A case series, Journal of Research and Rehabilitation Development,Volume 46 Number 7, 2009, Pages 985 996).