Tour de France news - Lance Armstrong: I'd have won with a clean field

The American won seven Tours but was stripped of them all in 2012 after admitting to doping dating back to 1996.

However, Armstrong insists that a great deal of his success was due to the amount of preparation he put into races and that doping merely levelled the playing field.

"We said we worked the hardest, had the best tactics, best team composition, best director, best equipment, best technology, recon the courses," he told NBC Sports.

"All the things we said, we did. We left out a part, but we did all that stuff. Because now this one thing is part of the story doesn't erase all that. All that happened. If you just had this one thing and did none of that, you get last."

When asked whether doping was a necessity for competing in Grand Tours, he replied: "That wasn't just a feeling, that was a fact.

"I don't want to make excuses for myself that everybody did it or we never could have won without it. Those are all true, but the buck stops with me. I'm the one who made the decision to do what I did, and it was ... I didn't want to go home, man. I was gonna stay.

"I knew there were going to be knives at this fight, not just fists. I knew there would be knives. I had knives, and then one day, people start showing up with guns.

"That's when you say, 'Do I either fly back to Plano, Texas, and not know what you're going to do? Or do you walk over to the gun store?' I walked to the gun store. I didn't want to go home."