Long before the days of running apps, designer running shoes and online marathon training programs, three-time Olympian Clarence DeMar self-coached his way to seven Boston Marathon victories- a record that remains unbroken today. More than one hundred years since winning his first marathon, Clarence "DeMarathon" DeMar is still known as one of the greatest American distance runners of all time. Marathon, DeMar's 1937 memoir, is a simple and honest...