fell running has its roots in agriculture rather than industry, and the levels of fitness resulted from spending all day up in the fells herding sheep, Walking races might be a better example of sport popular among the industrial working classes up north. btw I used factories and coal mines as examples of physically strenuous work because I am from the north but I'm sure there were equally strenuous and long hours for low pay jobs in London, the docks spring to mind or the meat pie factory on acre lane , next you'll be saying that convicts on the treadmill were the precursors of those yuppies you see sweating out dude food and imported lager out at that big posh gym opposite the craft beer place on clapham manor street.