i don't think anyone is arguing this - are the tour riders incrediblly good? of course. Is there tons of adrenaline? of courseat the same time, are kipchoge's marathon efforts other worldly. of course. how many national class runners could hang with kipchoge for even a 5k in his 2 hour marathon effort? his times are mind boggling.how do you compare what the tour guys do to kipchoge? my point is simply that you can't. the impact of running has side effects and prevents repeated efforts at the same intensity. because cycling doesn't have same stress on joints, etc. the two can't be compared. same with skate skiers. they are aerobic monsters - can one compare it to running? i don't see how... one has a side effect the other doesn't