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A common distinction between jogging and running is pace, and the common figure bandied about is 6mph. Others say you jog a 4h marathon but run a sub-4h marathon.
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Assuming that this is not your definition I believe that this interpretation smacks of elitism. Long distance running fortunately has very little of this, far less ime than long distance cycling does, but unfortunately, it still lingers in the egos of the self-appointed elite.
Average human walking pace is around 3mph so I would say that anything over 5mph is running, even if running slowly.
Incidentally, my first marathon was 4hrs 19 and I ran the last 12 miles in a lot of pain with a bandaged and swelling left knee. That qualifies, just, on the 6mph formula but fails the 4 hour formula. As it is far harder to run faster the longer the distance the 4hr marker over 26.2 miles seems very harsh indeed.