our sports teacher (USSR, mid-80ies) specifically instructed us to try to put feet "in-toe" when running - the logic was that most people are naturally slightly

our sports teacher (USSR, mid-80ies) specifically instructed us to try to put feet "in-toe" when running - the logic was that most people are naturally slightly "out-toe" so making explicit effort for "in-toe" would result in "straight-toe" during running and thus maximize the feet leverage.