Related to this, does anyone else get significant PEM after say, a 30-45 minute massage, whether lymph drainage or any soft tissue massage? I did not notice this during 10 yrs of "mild" ME/CFS, but now with moderate-severe ME, 40 minutes of massage gives significant PEM - 2 full days to recover to "typical" sickness level (20/24 hrs in bed).
Edit: I mention this because it might tell us something additional about the pathophysiology. The trigger for PEM does not require obvious physical (motor), sensory, or psychological energy. But, perhaps pressure on soft tissue creates chemical disequilibrium, so ATP is required for healing/restoration (?)
The sensory stimulation may not seem obvious because it is not one of the 5 common senses. But nerves can be specialized to sense much more than just the 5 common senses. Nerves in muscle tissue can sense anything from extracellular ATP due to micro-tears in the muscle, to inflammatory cytokines released in reparative macrophage infiltration of muscle tissue. Which may or may not be relevant to the ultimate pathophysiology.