<Tr> <Th> Children </Th> <Td> Paul, John, Stephen, Elizabeth </Td> </Tr> <Tr> <Th> Parent (s) </Th> <Td> Calvin Fixx, Marlys Fuller </Td> </Tr> <P> James Fuller "Jim" Fixx (April 23, 1932--July 20, 1984) was an American who authored the 1977 best - selling book The Complete Book of Running . He is credited with helping start America's fitness revolution, popularizing the sport of running and demonstrating the health benefits of regular jogging . He died of a heart attack while jogging at 52 years of age . His genetic predisposition for heart problems and other previous lifestyle factors may have caused his heart attack . </P> <P> Born in New York City, Fixx was a graduate of Trinity School in New York and Oberlin College in Ohio . His father, Calvin Fixx, was an editor at Time who worked with Robert Cantwell and Whittaker Chambers . </P>

Famous marathon runner who died of a heart attack