By the time I sat down with Lance Armstrong for this month's cover story  on Livestrong, his cancer foundation, I had seen him in July surrounded by rock-star size crowds at the Tour de France. I had also observed him far from the limelight, quietly visiting cancer patients at a Philadelphia hospital. That same weekend  in Philadelphia, in August, we spoke in a hotel suite before an awards dinner for Livestrong supporters .
His casual, fun demeanor was surprising, coming from a guy who often appears stone-faced, his eyes hidden behind wrap-around cycling shades. When I arrived in the room, he was laughing it up while trash tweeting with Cincinnati Bengals wide receiver Chad Ochocinco. Two of the most popular athletes on Twitter--Armstrong  has 2.6 million followers, Ochocinco  1.4 million--were daring each other to a bike race that also involved Bengals linebacker Dhani Jones , a new ambassador for Livestrong, and Bengals receiver Terrell Owens.
Before clearing the room for our interview, Armstrong read the back-and-forth tweets to Jones and a couple of Armstrong's buddies from Austin. Armstrong's parting taunt: "I will fly my ass to Cinci for this one. You don't want none of this."
In the following audio excerpts from our talk and from his remarks to the Livestrong crowd that night, you get a feel for the complexity of his personality, dimensions that the public rarely sees. Here's the sharp health-care advocate  who knows his material (no written speech or even notes). The impassioned  cancer survivor who's empathetic about the plight of others. And the jock with a frat-boy sense of humor. One thing you won't hear Armstrong talking about is the federal investigation  into doping allegations during his cycling career; his lawyers granted the interview with the condition that the topic was off-limits.
If you want to hear more about Armstrong and Livestrong, tune in tonight  at 10 p.m. to ESPN Radio's The Sporting Life  with host Jeremy Schaap . Schaap, who has covered Armstrong throughout his career, and I talk about my story and more.
In the meantime, here's Armstrong talking about how he knew Doug Ulman , a fellow survivor, athlete and nonprofit entrepreneur, was the right guy to run Livestrong.
About former president Bill Clinton. When Armstrong and Ulman shared a private flight with him, they discussed HIV/AIDS and cancer strategies.
About the Lance Armstrong Foundation becoming  Livestrong.
About his involvement with Livestrong as he eases into cycling retirement after a two-year comeback.
About how Livestrong is doing.
About "the wheel" of the disease, from detection to survivorship and the lack of access to care.
About how he loves a fight, especially the fight against cancer.
About him and his buddy John "College" Korioth and, well, let's just say Armstrong's able to find the comic relief in his cancer survival.
[Top image via LanceArmstrong.com ]