NEW : Media reports say Armstrong admitted to using performance-enhancing drugs . The Associated Press says he has been charged with doping and is expected in court on Monday. Interview with Winfrey lasted 2 1/2 hours , talk show queen tweets . Armstrong apologizes to cancer foundation workers for their stress .
NEW : Media reports say Armstrong admitted to using performance-enhancing drugs . Source tells CNN the former cyclist in talks to repay some sponsorship money . Interview with Winfrey lasted 2 1/2 hours , talk show queen tweets . Armstrong apologizes to cancer foundation workers for their stress .