Dave Brailsford and Tim Kerrison agreed to pass Chris Froome’s data for the past two years to the French sports daily L’Équipe, writes Matt Rendell.
They’ve said, "You can’t publish this, but you can let your favourite sports scientist look at it and draw his own conclusions."
L’Équipe recognises that there is no precedent for the race leader’s team making this type of data available.
So L’Équipe gave it to one of the France’s top leading experts in biomechanics and sports physiology, a university lecturer and researcher called Fred Grappe, who is on the Tour because he is also the coach of La Française des Jeux.
As a box at the bottom of the page explains, Dr Grappe is the pioneer of a measurement called Record Power Proﬁle (RPP), a new thing used by coaches and scientists to evaluate athletic performance and plan training intensities.
Grappe presented the concept of Record Power Proﬁle (RPP: formerly known as maximum mean power or MMP) in a research paper published in 2011 in the International Journal of Sports Medicine (the paper was co-written with another sports scientist, Julien Pinot, who is Thibault Pinot’s brother).
Put briefly, you take a rider’s weight, the time it has taken him to complete a climb, the power output data from his bike computer, and some other information, and you plot it all on a graph, adding comparable data from other efforts of different durations.
Soon a curve emerges, a Power Output - Time curve, which is a kind of personalised fingerprint of physical capacity: so-and-so can produce x amount of power for 5 minutes, y amount of power for 15 minutes, z amount of power over 40 minutes.
Obviously, any performances that break the curve are going to stand out as odd and raise question marks.
Fred Grappe has looked at the data and compiled Chris Froome’s athletic performance fingerprint. And he makes four observations:
- Froome’s power outputs vary in the normal way according to duration: for instance, he produces 60 watts less for a twenty-minute effort than for a sixty-minute exertion. What is more, there has been no significant change to his power output fingerprint over the last two years.
- His very high aerobic power output for a five minute effort suggests a) that his oxygen consumption (VO2 Max) is close to known physiological limits, and b) that he can produce 20 watts more than his main rivals at the Tour.
- His weight is very stable: 68 kg in the morning, with variations of no more than 900g. So his power expressed as watts per kg is very stable too, which is a good thing.
- He has excellent powers of recovery.
Grappe’s conclusion, as the headline halfway down page 2 says, is that "Froome’s performances are coherent."