The Weider brothers, Joe Weider and Ben Weider, were influential figures in the fitness and bodybuilding industry. Joe, often called the "Father of Bodybuilding," founded the Weider Company and created popular fitness magazines like Shape and Muscle & Fitness. He also developed the Weider System of Bodybuilding, which helped popularize weight training. Ben Weider, Joe's younger brother, was a key promoter of bodybuilding competitions. He co-founded the IFBB (International Federation of Bodybuilding) and played a significant role in establishing bodybuilding as a recognized sport. Together, the Weider brothers significantly shaped the fitness culture of the 20th century.