How Lance Armstrong Gets His Unusual Energy - New York Times: "Armstrong can ride up the mountains in France generating about 500 watts of power for 20 minutes, something a typical 25-year-old could do for only 30 seconds. A professional hockey player might last three minutes - and then throw up.
So how does he do it?
According to a scientist who studied Armstrong at regular intervals from 1992 to 1999, his prowess can be explained by a set of physiological changes that took place in his body over those seven years and that, in all probability, are continuing.
The changes are described in an article titled 'Improved Muscular Efficiency Displayed as Tour de France Champion Matures' in the June issue of The Journal of Applied Physiology."