Victoria Pendleton goes back into battle this weekend and, beneath her concentrated gaze, the fatigue and the scars are clearly visible. High up in the last row of an empty Manchester Velodrome, with the silence broken only by her quietly urgent voice and the low hum of wheels speeding past on the track below, Pendleton provides a revealing insight into a brutally competitive world.
"Believe me," she says softly, "it's a constant struggle. People say, 'Wow, you've achieved it all this year, two world championship wins and an Olympic gold medal.' And I think, 'Yeah, but how come I feel so unsatisfied and under pressure all over again?'"
Pendleton's bruised and candid intimacy as a sprint cyclist trashes the usual banalities of a sports interview. Rather than trundling out evasive platitudes about fulfilling a dream or maintaining her focus, she reveals the doubt and yearning that make her most human. "I am an insecure person," she says behind a set of spectacles that could teach Sarah Palin a thing or two about style. "I am emotional. I am a self-critical perfectionist."
She adjusts her glasses and then shakes her head as she reflects on that rapid-fire list of character traits while, out on the steeply banked track, the four men in GB's team pursuit keep their heads down and their legs churning in a ferocious training session for this weekend's World Cup in Manchester. "I'm terrible. I beat myself up the whole time because I'm striving for something I'll basically never achieve. I portray this image of confidence, of arrogance, and it's not really me. I'm never satisfied and I'm never content. It means I'm a bit of a mess some of the time. But I wouldn't be here talking to you if I was a different person."
The 28-year-old thinks hard when asked why, even after six world championship titles and an Olympic gold medal over the last three years, she still feels insecure. "I just want to prove that I am really good at something. And I haven't quite done that yet - at least not to myself. I know I could ride so much better, with more ease, with more finesse. I feel I'm nowhere near as good as I should be."
Those anxieties have risen back to the surface because, this weekend, Pendleton will try to win both the women's sprint and keirin in the World Cup. Some might regard it as a homecoming party for a triumphant team but Pendleton girds herself instead for another harsh and potentially humiliating personal examination. "I'm thinking, 'Holy Moly, I can't sneak under the radar here.' I'm coming in as world and Olympic champion and so I don't want to be explaining to the media afterwards about what went wrong. For me to be beaten now would be really distressing."
Pendleton is known for her assurance on the track, and some have accused her of vanity beyond it, but in person she is disarmingly vulnerable and frank. "Yesterday I was doing some times on the track and I was winding up for this really big effort and I felt fatigued even before I tried to get going. I thought, 'Oh gosh, this is really hideous.' I really can't maintain the form I was in at the world championships [in March] and the Olympics this long. I've worked at it these last few weeks but I'm struggling.
"I felt even worse at the national championships in September. I won the sprint and the keirin but my times weren't up to much and there was hardly anyone there. I felt quite tearful because the atmosphere was totally flat. It was a grim return to reality."
And yet, with the restless intensity that defines the world's best competitors in any vocation, Pendleton did not enjoy her Olympic experience. Apart from a traumatic wait as her team-mates won one gold medal after another while her event was decided on the last day of competition, even her victory was tinged with bluesy relief rather than ecstasy. "I was an emotional wreck beforehand because, while I was happy for everyone else, I was apprehensive about my ride. I worried that I would be the one person who let down the team. So winning was just a relief. And even that felt like a complete anti-climax. It was very surreal on the podium and as soon as I stepped off it I was, like, 'What on earth am I going to do now?' I found it quite hard to deal with. It was, like, I've got no purpose anymore."
Pendleton's voice trails away but, amid such soul-baring, she quickly reasserts her striking ambition. "I soon worked out that the only thing I could do was to get another gold medal. I need one. If 2012 goes to plan, winning the Olympics on my home turf, I might finally feel I've achieved the ultimate for me."
As if surprised by her voracious pursuit of the quintessential sporting victory, Pendleton uncovers another side to her character. "In some respects I crave a life where I don't feel guilty about staying out late or having a glass of champagne. I would quite like to have a normal life and just enjoy riding my bike - rather than doing everything with such purpose. It's the same with relationships. I struggle with them because in the past I haven't been committed enough to people. Gold medals have always been way above boyfriends - sorry! And that causes problems because it tells a guy he's not my priority."
Her latest relationship is, at least, working out more smoothly. "I haven't been going out with him for long - but he's been really understanding so far."
Pendleton is admirably open when asked whether she would like to have children. "Yeah, I really would. At the moment kids are simply not an option until 2012. But I must admit that as I get older the idea of having kids does become less repulsive than it was a few years ago. Maybe it's a hormonal thing but when I see kids now I sometimes think, 'Yeah, it would be nice to have some of my own.' As much as I love my life, and the fact I don't sit behind a desk and I experience wonderful things in amazing places, I still crave normality."
As a self-confessed girly-girl, who can follow up her musings on motherhood by confirming happily that she had been awarded the title of Britain's most glamorous Olympian in Beijing, Pendleton is a refreshing presence in professional sport's overheated world of strutting masculinity. She is also at her most engagingly polemical when taking on the Olympic chauvinism that means women track cyclists are only allowed a portion of the races on offer for their male counterparts.
"I don't know how they get away with it. Three events compared to seven for the men? That's not even half so it's particularly sexist. If this was swimming or athletics it wouldn't be allowed. There've been rumours that they might deign to add another women's event in 2012 but whether it's a sprint or an endurance [race]who knows? It pisses me off.
"And what other sport has to deal with the attitude we get as cyclists on the road? I certainly haven't noticed any sudden courtesy to cyclists in the wake of us being the most successful British team in the Olympics. I cycle to the velodrome most days and I have one narrow escape for every hour on the road. I just think, 'Holy shit, I could die on my bike out here.'
"To a cyclist, these bloody motorists might as well be running around with a loaded gun. When you have that sort of attitude towards cyclists how are we going to move our sport into the mainstream?"
The only way, as Pendleton herself stresses, is to keep winning - starting with another clinical surge this weekend. She might be riding on empty but there is such desire within her that it is easy to believe she will overcome her exhaustion and out-sprint her rivals yet again. Her earlier sense of deflation has clearly been obliterated by the time she gets around to revelling in the gladiatorial combat of sprint cycling.
"It's all about portraying this image of being strong and almost indestructible. Even if you're flapping away on the inside you have to walk out there with your shoulders back, your head up and this stern expression on your face. It's very serious. I'm quite good at it now - or maybe I'm just a good actress. At the world championships in 2006 I was sitting opposite the Chinese girl before the final and she looked so pale I knew I'd won even before I got on my bike.
"I thrive on that - and that's why I was sure I'd beat [Australia's] Anna Mears in the Olympic final. Anna used to push me about. She was a bit of a bully until I beat her in the worlds in 2005. The tables turned that day and she's not beaten me since. It's such a mental thing and when my mind's right I can beat anyone in the world."
A suddenly rejuvenated Pendleton carries out an amusing impersonation of the Queen, whom she met for the second time a couple of weeks ago when invited to Buckingham Palace. "Simon Clegg [the British Olympic chief] said, 'These are our gold medal winners,' pointing to us standing there with our medals around our necks. And the Queen said [in Pendleton's best imitation of the royal voice] 'Yes, I can see that.' She peered at me and asked, 'What do you do?' I said, 'I'm a track cyclist - like Chris Hoy.' I chucked in Chris's name - just in case."
Her laugh, this time, is relaxed but there is an icily determined glint to her gaze. She might be set for four more years of pain and anguish but, before she cycles back into ordinary life, a new path stretches out in front of her, gleaming with enough gold to finally settle all the anxieties and doubts that make her such a relentlessly successful champion. "Yeah," she suggests with a steely grin, "a few more people might know who I am by the end of 2012."