In November 1942, the Italian cyclist Fausto Coppi took "seven packets of amphetamine" to beat the world hour record on the track.  In 1960, the Danish rider Knud Enemark Jensen collapsed during the 100 km team time trial at the Olympic Games in Rome and died later in hospital. The autopsy showed he had taken amphetamine and another drug, Ronicol , which dilates the blood vessels. The chairman of the Dutch cycling federation, Piet van Dijk, said of Rome that "dope – whole cartloads – [were] used in such royal quantities." 
For example, anabolic steroids such as Testosterone have a tendency to promote water retention through their ability to be aromatized into Estrogen via the aromatase enzyme. While such an effect might not be a concern for a strength athlete or a powerlifter (such an effect might even be beneficial or desired in such sports), this is not a desired effect for athletes involved in sports that involve speed and swiftness, such as sprinting. Instead, a sprinter, for example, would more likely opt for an anabolic steroid such as Stanozolol ( Winstrol ) or Oxandrolone ( Anavar ), which are two anabolic steroids unable to convert into Estrogen and therefore the issue of water retention, and therefore the issue of added weight that would slow the athlete down is avoided. Many athletes may also elect to ‘stack’ anabolic steroids in a given cycle (stacking refers to the practice of combining more than one anabolic steroid in a cycle). In the case of cycle stacks, an individual might be able to increase the synergy and synergistic effects between the anabolic steroids to create a highly anabolic environment or to create a stack that might assist the user in favoring certain particular athletic or physique goals. These are some of the major reasons as to why the development of different types of steroids has been done.