been reading the Workwell Foundation papers on two-day CPET this week. as a PT I’ve ordered and interpreted exercise tests before. I thought I understood what a CPET measured. I did not understand what it measured for ME/CFS.
the protocol is this: patients do a maximal cardiopulmonary exercise test, rest overnight, then repeat the same test the following day. in healthy controls, even in deconditioned patients, day two performance holds roughly steady. anaerobic threshold, VO2 peak, ventilatory equivalents, all comparable to day one. in ME/CFS, day two collapses.
anaerobic threshold drops. oxygen utilization drops. numbers that looked borderline-normal on day one look genuinely impaired on day two. that’s what PEM looks like on paper.
it’s measurable. it’s repeatable. it’s not anxiety. and this is what’s been sitting with me: my neurologist’s workup, my cardiologist’s stress test, my full metabolic panel - all of it was captured at rest or in a single session.
none of it captured what happens to my physiology the day after I try to function. the pathology isn’t at baseline. it’s in the recovery window. I also keep thinking about how many patients I probably discharged as deconditioned over the years, when what they were describing was this, and I didn’t have the framework to recognise it.
has anyone managed to get a two-day CPET done through their consultant, and did it change what you were taken seriously about?