The athlete, 41, was recently stripped of the seven Tour de France titles he picked up between 1999 and 2005 and was banned from competitive cycling for life by officials at the U.S. Anti-Doping Agency after he decided to stop fighting the doping allegations which have blighted his sporting success.
As a result, Armstrong has chosen to step down from his role as the head of the Lance Armstrong Foundation, also known as the Livestrong charity, which he founded in 1997.
A statement released on Wednesday (17Oct12) reads: "This organisation, its mission and its supporters are incredibly dear to my heart. Today therefore, to spare the foundation any negative effects as a result of controversy surrounding my cycling career, I will conclude my chairmanship...
"My family and I have devoted our lives to the work of the foundation and that will not change. We plan to continue our service to the foundation and the cancer community. We will remain active advocates for cancer survivors and engaged supporters of the fight against cancer."
Armstrong was diagnosed with testicular cancer in 1996 and has since gone into remission.
A lengthy legal report published by agency chiefs last week (ends12Oct12) accused Armstrong, who has maintained his innocence throughout all investigations, of helping to run "the most sophisticated" doping program the sport has ever seen.