Lance Armstrong's story was one of the most inspirational in sports: the cyclist overcame testicular cancer to win seven straight Tour de France titles from 1999 to 2005. But the story took a radical turn, as more and more people came out and said that he doped. Throughout the years Armstrong steadfastly maintained that he did not dope -- that is, until now. He admitted in an interview with Oprah Winfrey that he did, in fact, use drugs to help him win the Tour de France. Here's a timeline of some critical dates throughout Armstrong's career. Armstrong turned professional after the 1992 Summer Olympics, and joined the Motorola Cycling Team.