"This biological decrease in energy is specific to those with PEM and not seen in other chronic illnesses."
I have to disagree. In addition to Long Covid, I think this post-exertional malaise (PEM) is also caused by mitochondrial issues associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). I was hoping that lenz would have demonstrated success in treating Long Covid, and that it would help me with ME/CSF. I'm still hopeful.