That seems to be a universal human standard as far as efficiency for an endurance sport, holds pretty much true for elite distance runners. In the TdF there are specialists (sprinters for example) who are bigger because they basically draft off other riders until the last 3-400 meters and then need to be big enough to support leg muscles that can generate brief bursts of speed exceeding 50mph. The GC guys (general classification, the people with a chance at the overall win) are specialists at nothing but do everything (climbing, time trialing, sprinting) well