Coach Lananna walked over to explain. “I can’t prove this,� he explained, “but I believe when my runners train barefoot, they run faster and suffer fewer injuries.�
"Vin Lananna, track coach at Stanford University was instrumental in convincing Nike, that runners, in order to avoid injury, needed less shoe, not more. Years of having his athletes train barefoot regularly on the campus golf course had helped persuade him that runners who ran regularly without shoes were less prone to stress fractures,plantar fasciitisand a host of other overuse injuries. Running barefoot, Lananna believed, developed stronger feet and ankles that were, in turn, less prone to damage."
https://runningmagazine.ca/bloggers/barefoot-running-whats-old-is-new/