The 1500m imposes upon you the requirement that you have to actually be FAST, rather than merely having endurance. He isn't like Lance, whose race takes hours a day for many days. He can expect to have to race for less than 4 minutes at a time, and runs at most 3 races in a few days with the first two (heats and semis of championships) being quite a bit easier. Moreover his races aren't always hard from the time the gun goes off--a lot of these races are run quite a bit slower than the capabilities of even the worst runners in the field, because no one wants to wear themselves out by leading a fast race. Then the pace goes insane on the last lap or two and to succeed you have to be the kind of runner that could run well under 50 seconds for a quarter mile when fresh, as well as being truly comfortable with, say, 3:56 mile pace.