Filmmaker Alex Gibney began working on his documentary about Lance Armstrong in 2009, back when Armstrong was a famed cancer survivor and hero in the world of cycling.
In the trailer for the documentary "The Armstrong Lie," Gibney recalls how Armstrong lied to him about using steroids. Watch.
"This is not a story about doping. It's a story about power," Gibney said. "And the story became hanging on to that power."
"The Armstrong Lie" will ride into theaters soon.