I’ve upped my treadmill time recently, not to accelerate any possible health gains but more to counteract a bout of evening activities that would preclude its usage, and after two days of 50% more than normal  I had significant lower back pain to the point that I had trouble sitting.  This has happened before, although usually due to me moving something larger than I should have and the solution was always to walk it off.  I tried it again in this case and it appears to have worked.  So the cause of my back pain was excessive walking and the solution to my back pain was even more walking.  I think some people have died in the process of learning if coke and whiskey work on the same principle.