Lance Armstrong participates in a mountain biking competition in Colorado . Hide Caption 8 of 12 Photos:Photos: `` I do n't have anything to worry about , '' he says , insisting he 's at ease with move . An anti-doping agency has accused him of performance-enhancing drug violations .
Lance Armstrong participates in a mountain biking competition in Colorado . He talks 2 days after announcing he wo n't challenge a doping agency 's charges . `` I do n't have anything to worry about , '' he says , insisting he 's at ease with move . An anti-doping agency has accused him of performance-enhancing drug violations .