Jim Fixx, American runner and author (d. 1984)
James Fuller Fixx (April 23, 1932 – July 20, 1984) was an American who wrote the 1977 best-selling book The Complete Book of Running. He is credited with helping start America's fitness revolution by 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.