"Pete Kennaugh was laughing at the end of the stage," said Kerrison. "He said the way Chris rode that climb was exactly what we do in training every second day. Our training is much more than just doing intervals at a constant pace for a set amount of time; [some of it] is about being able to handle changes of pace – to go from, say, 350 watts to 650 watts for a few seconds to attack and get a gap on a rider who is trying to follow, then come back down to 350 watts."
Kerrison's term for this kind of interval training is spiked efforts, "where we make an effort then come back to a very high but sustainable pace. The energy systems have to have the ability to produce that power, which will produce a load of lactate in the muscle, because you are well above anaerobic threshold [the point at which the body is producing more than it can handle of the lactate which is the main limiting factor in intense efforts] – then come down to a very high level, just sub-threshold, and clean out the lactate, the effects of the attack. Pretty much all our training is based on that. The guys in the team who train that way look at [Froome's attack] and think, 'He's rehearsed that way of riding, three or four times a week for the last two years'."
Most often when climbers make their attacks on a mountain, they do it standing on the pedals to gain the maximum amount of leverage from the arms and upper body. Froome remained seated while making his attack on Contador, however. There is a clear advantage in doing this, Kerrison believes: working in a wind tunnel has shown Sky that there is much less drag when a cyclist remains sitting down. That applies even at relatively low climbing speeds.