Alex Gibney’s The Armstrong Lies is fascinating as far as it goes but it may not go as far as you would like, and may not ask the questions you would like. It’s a documentary portrait of the American cyclist Lance Armstrong: seven-time winner of the Tour de France, worldwide symbol of physical courage (having survived testicular cancer in his twenties), founder of the Livestrong Foundation, which has raised millions for cancer sufferers, and something else. It’ll come to me in a minute. Talk among yourselves. Oh, yes. Cheat. Also, liar. He lived a cheating lie, all day, every day, throughout his sporting career. He lived a cheating lie even as he is pulling on his socks or taking the rubbish out. But Gibney never gets to the heart of him. It is fully possible there is no heart to get to — Armstrong is a cold-blooded customer — but I wanted to see him trying. So, in this way, The Armstrong Lie huffs and puffs and pedals like mad but never quite makes it over the finish line.

Interestingly, yet contaminatingly, as Gibney never entirely foregoes his admiring tone, this is not the film he originally set out to make. He set out to make a straightforward, ‘positive’ comeback movie following Armstrong’s attempt to win the Tour de France in 2009. (Having retired in 2005 after his seven consecutive wins, Armstrong could not keep away.) Gibney had the film done and dusted when Armstrong was suddenly forced, after years of furious denials, to come clean about his doping habits, and confessed all to Oprah, as you would. (Confessing all to Oprah is probably the next best thing to papal absolution. One day, I would like to confess all to Oprah.) So Gibney went back to his shot footage, seeing it in a new light, and topped it up with a post-confession interview.

So, the ways in which it is fascinating. OK, it is fascinating about the Tour de France, although maybe I only felt that because I knew nothing about it. I honestly thought men in jerseys got on bikes and the fastest was the winner, and that was that — I will confess this to Oprah; she will forgive me — but now I understand it is a highly gruelling, complex, strategic team endeavour. So I learned that, and I also learned how astonishingly abundant drug use is in cycling. Go back over the years and it’s almost impossible to pick out any rider who was certainly clean. And Armstrong, like the others, used testosterone, growth hormone, EPO — which increases oxygen in the blood, and was undetectable for many years — and blood transfusions. People must have known, you would think. Yes, just as people must have known about Jimmy Savile, but who was prepared to say anything? Actually, in this instance, some did. Former team-mates, former employees and various journalists all accused Armstrong, but he always saw them off with a light laugh. I’m kidding. He retaliated with a biblical vengeance.

He sued. He bullied. He ruined careers. When a former team-mate testified against him, he made sure he never cycled competitively again, and as for that team-mate’s wife, who also testified, he left her a voicemail message that said: ‘I hope someone breaks a baseball bat over your head.’ Although I’m no psychiatrist, even though I’d clearly make a very good one, Armstrong obviously suffers from a narcissistic personality disorder. He displays no shame, no remorse, no understanding of how he harmed people. Even in the post-confession interview, when he is saying ‘sorry’, his look is saying: ‘Sorry? Screw you, loser! I’m Lance Armstrong!’ Such a personality doesn’t come from nowhere, but there is no digging around. Gibney, whose previous documentaries (We Steal Secrets: The Story of WikiLeaks; Enron: The Smartest Guys in the Room) have been probing, deals with Armstrong’s entire childhood in one single sentence, saying he was raised by his mother and never knew his father. Did his father’s abandonment create the deep-seated sense of worthlessness narcissism always seeks to defend? Is this where his horror of being a ‘loser’ comes from? Is this why he must be a ‘winner’, whatever it takes? We’ll never know. Gibney does not attempt to talk to family members, childhood friends, his first coach and, if he did and was rebuffed, why didn’t he say so? Similarly, there is footage of Armstrong with his little daughters. What is he like as husband and father?, I wanted to know. Again, nothing.

But most regrettably, Gibney does not make Armstrong squirm, and does not ask the questions that might have made Armstrong squirm, assuming he can squirm. He allows Armstrong to say: ‘I didn’t live a lot of lies, but I lived one big one,’ as if that makes it OK, and as if it even makes sense. And he ends by saying of his subject: ‘The cruelty he showed off the bike is what allowed him to win on the bike,’ even though Armstrong didn’t win. He cheated. (OK, so did everyone else, but that’s not the point.) As I said, it’s entirely possible you can’t get to the heart of Armstrong because there is no heart, but I’d like to have seen someone have a go.