Brailsford considers releasing limited Froome data on Tour de France rest day

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Dave Brailsford has said that Team Sky may release limited data into the public domain in response to some of the estimates of Chris Froome’s power output that have been published during this Tour de France.

Froome’s performance in winning atop La Pierre-Saint-Martin last week has come under particular scrutiny, with exercise physiologist Pierre Sallet claiming on France Télévisions’ "Stade 2" programme on Sunday evening that the Sky rider had produced 7.04 watts/kg during his effort.

Sallet did not elaborate, however, on the methodology he had used to calculate Froome’s power output. Brailsford was a guest on the show, and at the start of stage 16 in Bourg-en-Péage on Monday morning, he said that he had not been told how Sallet had arrived at that figure.

"No, no. They want transparency but they won’t give you the mathematical model of the estimations that they’re using," Brailsford told a small group of reporters outside the Sky bus. "And everybody knows that when you estimate, there’s a margin for error. There was a good paper published recently by Yann Le Meur about exactly that, and in the scientific paper they said there was a plus or minus 6-10% error. There are so many variables you have to take into consideration."

While Froome looked to place the blame on sections of the media for the aggression displayed towards his team by supporters on the roadside in recent days, Brailsford repeated his calls for the UCI to add a power analysis element to its current biological passport system.

"I don’t think you can say that it’s only the media because if everybody believed in the tests, then you wouldn’t be in this situation," Brailsford said. "The problem is that everybody doesn’t believe in the tests, and I think that’s the responsibility of the UCI – to manage things better, to be more proactive and try to think a bit outside the box maybe to find a more innovative solution to try and reassure the people."

The implementation of such a system would take considerable time, however – indeed, the idea has already been floated in various forms over the past five years – and Brailsford was asked if there was information his team could provide now in order to allay the suspicions that have surrounded some of their performances.

"I think we’ve faced the same questions last time around [2013]. We agreed to give all of our power data to UK Anti-Doping and the CADF. The CADF didn’t want it and UK Anti-Doping, I don’t think they did anything with it. But we were willing to give it to an independent body and we’d do the same now, we’ve got no problem with that at all," Brailsford said.

"I think we’ll have a look at it tonight and for the rest day we might just release an average cadence or the average power.

"But you’ve got to bear in mind that there are issues like different power-meters, oval rings against round rings. You’ve got to understand all of these things before you start interpreting the numbers that you’ve got. You’ve got to be careful with it, just throwing numbers out there, but equally I think there’s no harm in sharing a few numbers just to give some concrete evidence of where we’re at."