Ben Foster Took Performance-Enhancing Drugs to Prepare for Lance Armstrong Role

"For my investigation it was important for me privately to understand it. And they work," he says about preparing for 'The Program.'

It's not uncommon for actors to go through the same experiences as their subjects in preparation for their roles. The extremes that Christian Bale has endured over the course of his career are well-documented.

But for Ben Foster, who plays Lance Armstrong in Stephen Frears' The Program — which has its world premiere in Toronto on Sept. 13 — his research involved giving performance-enhancing drugs a go.

"For my investigation it was important for me privately to understand it. And they work," he told The Guardian, although he stopped short of naming the drugs he tried. "Even discussing it feels tricky because it isn't something I'd recommend to fellow actors."

Foster also admitted that he'd "only just recovered physically" from the experience. "There's a lot of fallout. Doping affects your mind. It doesn't make you feel high. There are behaviors when you've got those chemicals running through your body that serve you on the bike, but which, when you're not...."

He added: "I don’t know how to separate the chemical influence from the psychological attachment I had to the character. If it’s working, it keeps you up at night. This is losing your marbles, right? They’re definitely rolling around. They’re under the couch but they’re retrievable."

A rep for Foster later confirmed to The Hollywood Reporter that the actor's preparatory drug-taking had been done under the "guidance and supervision of a doctor."