Lance Armstrong said "nobody needs to cry for me" after the US Anti-Doping Agency (USADA) wiped his seven Tour de France titles from the record books and imposed a lifetime ban from professional cycling.
Speaking after finishing a 36 mile mountain bike race, Armstrong said: "I'm more at ease now than I have been in 10 years".
Armstrong recently announced he would no longer challenge the USADA's allegations against him but the cyclist again denied that he took banned substances in his career.
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Mr Kim has made two recent visits to China.
The study looked at the development of 422 children over the course of eight years.
The president said they will come into force if China refuses to change its practices.