Chris Froome releases performance data - but will it silence critics?

Tour de France champion Chris Froome insists that he is riding clean as he releases performance data that he hopes will go some way towards silencing those who believe he is cheating.

The data have been released in an article written for Esquire magazine by cycling journalist and author Richard Moore.

He accompanied Froome, as well as the Team Sky rider's wife Michelle who is also his manager, to the GSK High Performance Lab in London in August.

His VO2 max– a measure of the maximum rate amount of oxygen the body can use – was 84.6.

After adjustment for the weight he had been during the Tour de France, 67kg against the  69.9kg when tested, the figure was 88.2 – in line with the power data Team Sky released during the Tour de France.

Phillip Bell, one of the senior sports scientists at the GSK High Performance Lab, said “Froome’s values are close to what we believe are the upper limits for VO2 peak in humans.”

Moore notes that they are below the 92.5 produced by Greg Lemond, who won the Tour de France three times.

Froome also underwent tests to establish his power output, with a peak of 525 watts and a sustained power output figure of 419 watts, which equates to 5.98 watts per kilogram or, at the weight Froome was at during the Tour de France, 6.25w/kg.

> Team Sky release Chris Froome's data in bid to prove he's clean

Among those present at the tests was Jeroen Swart, an expert on sports physiology from the University of Cape Town and who is a member of South Africa's anti-doping review commission.

In a subsequent meeting with Moore, he explained: “These tests give us an idea of what intensity Chris would be able to sustain for 20–40 minutes, which is roughly the length of a Tour climb.

“Chris’s peak power is 525 watts, which corresponds to 7.51w/kg: a massive figure. But the interesting thing is that the [sustained] figure of 6w/kg — which is basically what he produced in the lab — is 79.8 per cent of his peak power.

“That’s a completely reasonable percentage,” he added.

The article also publishes data from the tests undertaken at the UCI's World Cycling Centre in 2007.

Froome – at 75.6kg, much heavier than he is now and had more body fat, 16.9 per cent.

“Frankly, for an elite cyclist that’s chubby,” Swart said. “But he produced better figures: peak power of 540, threshold of 420 — we made it 419, so it’s one watt less.”

The rider's VO2 max in 2007 was recorded as 80.2.

Swart said: “The engine was there all along. He just lost the fat.”

Speaking to BBC Radio 5 Live yesterday, Sir Bradley Wiggins, to whom Froome was runner-up in the 2012 Tour de France, said he did not believe the release of the data would make the sceptics change their minds.

"It's what people have called for and Chris and has done it, so hats off to him," he said.

"I'm sure it is not something for them to live and die by, or if it will change anything. It is a small step maybe."

He also spoke of the hostility Froome endured from some quarters during this year's Tour.

"I think to be under that amount of scrutiny for three weeks and do what he did was admirable,” he said.

“It shows his physical and mental strength to be able to deal with that.

"Being spat at – sport is hard enough as it is without facing what he had to face," Wiggins added.

> Froome's training data hacked, says Brailsford

But for some, the suspicions are already set in stone and conclusions drawn, no matter how many tests Froome undergoes.

Moore met Antoine Vayer, one-time trainer to the Festina team who, while not a qualified sports scientist, believes his experience of working within cycling during a period of widespread doping gives him expertise in this field.

Vayer, who this year suggested Froome might have a concealed motor in his bike – “nuts” was the rider's reaction when the journalist told him – insists it is too late for Froome to convince him he is clean.

He told Moore: “Nothing would convince me. He should have called me a year ago and said, ‘Vayer, you make me angry, let’s sit together.’

“If you are clean and you have doubters, you phone your doubters, don’t you think? Because I am quite influential,” he added.

But Froome maintained: “I know what I’ve done to get here. I’m the only one who can really say 100 per cent that I’m clean.

“I haven’t broken the rules. I haven’t cheated. I haven’t taken any secret substance that isn’t known of yet.

“I know my results will stand the test of time, that 10, 15 years down the line people won’t say, ‘Ah, so that was his secret.’ There isn’t a secret.”