Disgraced cycling star Lance Armstrong has just admitted that his own doping use may have caused him to get testicular cancer. He also confessed that he first started doping at the age of 21, even though he was not caught for another 19 years.

Daily Mail reported that Armstrong was finally caught doping in 2012, and he was stripped of his seven Tour de France titles the next year, much to the shock of the entire world. In the upcoming ESPN documentary “Lance,” Armstrong opens up about his doping and the career he had that is now infamous.

At one point in the documentary, Armstrong was asked directly if his doping led to him getting testicular cancer.

“You know, I don’t know the answer to that. I don’t want to say no, because I don’t think that’s right either. I don’t know if it’s yes or no, but I certainly wouldn’t say no,” Armstrong said. “The only thing I will tell you is, the only time in my life that I ever did growth hormone was the 1996 season. And so just in my head, I’m like, growth… growing hormones and cells, like… if anything good needs to be grown, it does. But wouldn’t it also make sense that if anything bad is there, that it too would grow?”

Armstrong managed to beat cancer and return to cycling in 1998, only to immediately start doping again. When asked how old he was when he started doping, Armstrong said, “probably 21.”

He was not crowned the road race world champion until he was 22, so it appears he was doping before the first major win of his career.

“There’s a bunch of ways to define doping. The easiest way to define it is ‘breaking the rules,” Armstrong can be seen saying in a clip released by ESPN. “So, were we getting injections of vitamins and other things like that at an earlier age?’ ‘Yes. But they weren’t illegal, so that… You know…”

Marina Zenovich, the filmmaker behind the movie, asked Armstrong if he knew what was in the syringe.

“Of course. Oh, yeah, yeah, yeah. Come on,” he replied. “I’m not one of those guys. I was always, ‘Ooh – what do we have here?’ I always asked, and I always knew, and I always made the decision on my own. Nobody said, ‘Don’t ask; this is what you’re getting.'”

“I never, ever would have gone for that,” Armstrong added. “I educated myself on what was being given, and I chose to do it.”

“Lance” will be airing in two parts on ESPN on May 24 and 31.