these are the interesting bits from the Equipe article, Grappe’s observations:
First observation: His power drops off normally
“The relationship between power and time is similar to what is known and is observed in all the riders that have been established in the record power profile (RPP),” Grappe told Equipe.
“It shows, for example, a significant and normal power reduction of 60 watts (0.88 w/kg) between twenty and sixty minutes efforts. On average an athlete loses fifty watts in this time interval. The RPP that Froome has over two years does not seem to show any abnormality in its fundamental structure. In other words, the power data of the last two years is consistent with the profile that it represents. The performances he made on Ax 3 Domaines and Ventoux were to be expected in view of his PPR. During the last two years, his profile has not changed. It appears that the potential that he has today is similar to the one he had in 2011.“
Second observation: an exceptional aerobic potential
“The extremely high maximal aerobic power (efforts of five minutes) confirms that he has an extraordinary high aerobic potential, which means he has a V02 max (this has never been measured in the laboratory by his team) close to the limits of known physiological science.“
“The exceptional power that he is able to develop during maximum efforts of five minutes gives him a certain reserve (of strength) compared to other athletes. This gives an indication of why he is capable of performing on the final climbs. It is estimated that, compared to his main rivals, he has a margin of 20 watts extra power. It is this difference that can be seen for example between him and his main rivals on the climbs and Ax 3 Domaines du Ventoux.”
Third observation: a very stable weight
“His average weight over the two years is 68 kg (in the morning) with less than 900g variations. This shows that the power he develops over two years is relatively stable when expressed in watts per kilogram (W/kg), a very important indication of the performances he has shown.”
Fourth observation: excellent recovery
“It is evident that to be able to operate with a power profile near 100% of his maximum, Chris Froome must have excellent ability to recovery between stages. Because if the level of fatigue accumulates too much, it is no longer possible to be close to his records.”
Grappe also studied Froome’s performance in Wednesday’s time trial, saying: “the average power output was still a very well integrated into its power profile once, and therefore completely expected.”