The British sprinter was banned for two years after he had taken anabolic steroid THG.
Any medals he had won since mid-2002, when he first admitted using THG, were taken from him. He was also asked to pay back any earnings he had made in his athletic career during the time he was taking the drugs.
The American track and field athlete won 3 gold medals and 2 bronze medals at the 2000 Olympics but was later stripped of the titles after admitting to steroid use.
She was also given a two-year ban from track and field competitions by the United States Anti-Doping Agency.
The Tour de France cyclist won the race seven years in a row - but had those victories stripped from him after it was found he had been taking drugs to help his performance during this time.
He also received a lifetime ban from competing in all sports which follow the Word Anti-Doping code.
The American sprinter, who won the 100 and 200m at Helsinki in 2005, was banned for 4 years after he had been tested positive for testosterone.
He previously had been give a one-year ban for testing positive for amphetamines.
All of these athletes are prime examples of the risks associated with taking steroids, not only for your health but also your sporting career. It's not worth the risk.
Find out how to say no if you're feeling pressured to take steroids, and how you can improve your sport skills the natural way.
Head back to the Choices for Life campaign page.