How long can one continue the race week/ non race week schedule before having to start a base phase again?
Bekele, and other world class distance runners can run very very fast because they have very high aerobic capacity that they can run very close to their top speed without getting into anaerobic state. It all comes down to mean this (and I'll just give you some ridiculous hypothetical numbers): if Bekele, or Ethiopean runner A, can run 200m all out in 22 seconds and you can run 200 in 22.5, it's not that much of a difference as far as "speed" is concerned. But if Ethiopean A is coasting at 24 seconds aerobically because he has such a huge aerobic base and his max aerobic speed is, say, 25 seconds, while you're getting into anaerobic at 25 per 200 speed and getting lactic acid up to your ears because you have very poor aerobic base and your max aerobic speed is only 26 seconds, it's not even a contest before you reach the final 200m mark. But many coaches and athletes misinterprete this picture, trying to improve his "speed" down to 21.5 seconds because he gets left behind in the final 200m = he needs more speed. This is the principle Lydiard has been trying to teach in the last half century and what Dr. Snell was trying to emphasize at the Las Vegas convention several years ago. This concept makes sense to me.
Have I been spelling "Ethiopean" correctly?
I completely agree with that Nobby.
When Lydiard first came to the US, most people were interval-trained. He told them that his runners did 100 miles a week of training. Some people tried it but, because they weren't as well-conditioned as his runners, did it slow (just to survive). They figured running this slow would not make you a fast competitor. So Lydiard training is no good. For decades, Lydiard had to fight against such thinking by telling them also that "Snell and Davies did 20X400 in 60 seconds or faster. How much speed to you need?"
Marathon conditioning, or aerobic base building phase, is merely prerequisit to more exacting training phases. Because his runners were so much stronger than others from all the miles that they ran, they could do much more faster or more race specific training than other runners. This is the whole principles of the Lydiard program that has been applied to other sports like rugby or kayaking--those who have developed their stamina can do more competition-specific training than others. While others might practice "passing of the rugby ball while running as fast as you can" 20 times, if you developed adequate stamina, you do that 40 times.