The novelist Haruki Murakami describes himself as "a runner and a writer".  The two are inextricably intertwined elements of his whole being. As a runner and a writer, I wholeheartedly agree. What is it about the physical exertion of running that is so vital for the parallel process of creative release? How do the two activities mirror each other such that the Holy Grail of "the flow" finally becomes attainable?