Phys.org describes a new paper in PNAS on how glycolysis changes gene expression via histone modification. This affects quite a range of different genes, but is apparently not lethal, even for cells. I can't help but wonder if post-exertional malaise depends on clearing molecules like methylgloxal. This is the beginning of a whole new line of research, not necessarily an answer to our specific problems. It is, however, suggestive.