Yes and no... Back in 2003 Armstrong was finishing some of the mountain stages of the Dauphine with an average close to 500watts for the last 30 to 40 minute climbs of the day. Yes, you have to recover to be able to do well day after day after day... but then there's the matter of actually putting out 500watts for >30minutes regardless of where abouts in the stage you're at - let alone after a week of hard racing.
Yes, its called EPO, autologous blood doping, HGH ... do you really think that amidst all the other dopers, who trained just as hard, with higher VO2Max levels, but without the better teammates, would lose to LA year after year...com'on use some elemental logic. It's ok, he cheated and you'll get over it. Did you think Tiger woods and Marion Jones...(insert squeaky clean idol) were innocent and pure...I did. And, look at them now. There is even suspicion that Tiger hired a Canadian MD to 'assist' him with training and recovery and now people are asking themselves how Tiger went from being a thin young man with sinewy muscles to the bulked up man crushing golf balls farther than most. Oh, he must work out more than the rest and its 'leg/knee snap' that gives him the advantage (but I digress)
That's just under the same amount of power that Indurain put out during his hour record... and not far off from what Boardman put out for the pursuit record that he's held for over a decade.