So you admit that there is no research showing that healthy people on bed rest perform abnormally on the 2 day CPET. There is only your suspicion, which is contradictory to the existing evidence. Deconditioned controls and other healthy people do a bit better on day 2. There is no reason to suspect that healthy people with an even greater degree of deconditioning function in a diametrically different manner from patients with a lesser degree of deconditioning. While such a thing might be marginally possible, it's extremely dishonest to claim it as being proven. The relevant studies, which you obviously haven't read, clearly state that VO2max was achieved, meaning that objective indications of maximal effort were met. This includes heart rate near or at predicted max, respiratory quotient of 1.1 or higher, and a third one I can't remember. Maybe you should read the studies so that you can critique them without making embarrassingly inaccurate comments about them. I believe that non-max testing has been used for more seriously afflicted patients, and those who are unwilling to risk a long-term relapse. And there is probably research in the works to see how well non-maximal testing matches up with maximal testing, to see if it's feasible to test patients in that matter without half killing them in the process. But the research papers people are referring to here as proof of a pathological reaction to exertion were ones where VO2max was used in the typical and appropriate manner. Since when do patients have to reach a certain speed for the CPET to be valid?