The Comparison Problem
The deeper damage was not to any single race. It was to the sport's ability to compare across time. Distance running's cultural value rests heavily on times, because a marathon result is meant to be commensurable with a marathon result from another decade in a way that a score in a team sport is not. An equipment change that improves economy across the board breaks that, and it breaks it in a way that cannot be repaired retroactively.
There is no honest adjustment available. The benefit varies between runners, since it depends on stride mechanics, mass and pace, so no single correction factor could be applied to old results even in principle. Nor can the shoes be uninvented. What the sport was left with is an era boundary: performances before and after are both legitimate, achieved under the rules in force at the time, and not straightforwardly comparable. That is a genuine loss, and it is the strongest argument the critics had, stronger than any claim about individual unfairness.
