The widespread use of PEDs in the 1960s and 1970s, particularly in sports like cycling, track and field, and weightlifting, led to growing concerns about fairness and athlete safety. The death of Danish cyclist Knud Enemark Jensen during the 1960 Rome Olympics, which was later linked to amphetamine use, marked a turning point in the fight against doping. This tragic incident spurred the establishment of formal anti-doping regulations.