Joe Weider is the most successful publisher of weight training/fitness magazines in the 20th century. He began his publishing career in 1940 with Your Physique and went on to launch many other magazines, including Muscle Power, Muscle & Fitness, Flex, Shape, and Men’s Fitness. He also had a successful food supplement business and, with his brother, Ben, he founded the International Federation of Bodybuilders. Since the 1950s he and his wife Betty have been central figures in fitness.