I recently read some old RW's (back when it dealt with RUNNING) and viewed the 1960, 1964 and 1973 Olympic marathons on video on YOUTUBE>
It still impresses me that those guys did 100-mile weeks
(or more) in trainers that were, for all intents and purposes, bowling shoes. And with no ill effects.
I suspect that over time there was a winnowing out process, but how do YOU believe these runners of a previous generation dealt with the aforementioned, and never had PF or achilles injuries or chrondomalacia or ITBS?
Amazing.