In the first known doping incident, coaches pumped a dangerous mix of strychnine and pure egg whites into Thomas Hicks before his marathon at the 1904 St. Louis Olympics. In the absence of guidelines at the time, he was declared the winner of the race - even after collapsing at the finishing line and hallucinating for hours. The boost may nearly have cost Hicks his life.

Argentine soccer ace Diego Maradona has battled with substance abuse on two separate fronts: During the 1980s, he developed a serious cocaine habit that would follow him throughout his life and lead to some serious health scares, but he also tested positively for ephedrine in 1994, provoking a FIFA ban and the end of his prolific career as a midfielder.

Born as Heidi, Krieger was a female shot putter for East Germany at the height of the Cold War. Communist officials fed Krieger with staggering amounts of steroids, altering her appearance. Krieger began to publicly identify as transgender and later opted to have gender reassignment surgery, becoming Andreas.

A successful Canadian sprinter with a stellar track record, Johnson's doping scandal overshadowed much of the 1988 Seoul Olympics. When blood samples tested positive for stanozolol, he was disqualified three days after winning the gold medal in the 100-meter sprint. Though Johnson admitted to doping, he maintained that he had never taken stanolozol - implying that he might have been set up.

Marion Jones was sentenced to six months in prison in 2008 after lying to US federal investigators about her part in the Bay Area Laboratory Co-Operative (BALCO) doping scandal. Jones, the most prominent athlete linked to the scandal, had denied all allegations against her but later tested positive for tetrahydrogestrinone supplied by BALCO, leading to the end of her career.

Alex Rodriguez is one of the most successful baseball players of all time, producing numbers rarely seen since the days of fellow Yankees Joe DiMaggio in the 1940s and Babe Ruth in the '20s. Rodriguez was suspended for the 2014 season after admitting to steroid abuse. He has made a comeback and hopes to redeem himself by completing 700 home runs before he retires from the sport. He has 678.

Ullrich was German cycling's poster child. He won the 1997 Tour de France and two medals at the 2000 Sydney Olympics and continued to compete internationally for several years before doping allegations first arose in 2006. He managed to dodge these until 2012, when a Court of Arbitration for Sport ruling found that he had used steroids for many years.

A number of investigations between 2010 and 2012 led to Lance Armstrong's monumental downfall in January 2013. Although allegations had been levelled at him repeatedly, Armstrong managed to hide his steroid abuse for years. Having conquered testicular cancer, Armstrong was once a national hero who even hinted at a future career in politics in his native Texas. That's now history.