Tyler Hamilton

Professional cyclist Tyler Hamilton won a gold medal at the 2004 Summer Olympics in the men's individual time trial. The result however was questioned after he failed blood tests for doping.

On April 17, 2009, Hamilton announced he would retire from cycling after testing positive for a banned substance yet again. He previously served a two-year suspension for doping from 2005 to 2007. The penalty for the 2009 result could be as much as eight years, virtually ending the career of the 38-year-old racer.The New York Times: Gold Medal-Winning Cyclist Tests Positive...

Hamilton originally began his career as a skier, but a back injury on college pushed him into cycling. Turning pro in 1995, he competed with the U.S. Postal Service racing team until 2001, including competing in the 2000 Tour de France, finishing the 19th stage in fourth place. Hamilton was a member of the Denmark-based Team CSC in 2002 and 2003, again competing in the Tour de France, winning the 16th stage in 2003. In 2004, he moved to the Swiss Phonak racing team.Velobios.com: Tyler Hamilton Racing Profile

After winning the gold medal at the 2004 Summer Olympics in Athens, Hamilton came under fire as blood tests revealed a banned substance in his system. He denied the claim, stating that he received a blood transfusion, which would have increased his red blood cell count. Although he did not lose his medal, he did receive a two-year suspension from racing, starting in 2005.The New York Times: Gold Medal-Winning Cyclist Tests Positive...

After serving his suspension, Hamilton joined the Tinkoff Credit Systems team in 2007, but failed to qualify for the 2008 Summer Olympics. He moved over to Rock Racing in 2008, winning the Tour of Qinghai Lake and USPRO Road Race Championships.Velobios.com: Tyler Hamilton Racing Profile