You've got to realize; Lydiard was always very meticulous and structured in his approach. If not, he wouldn't have given his athletes a season's long day-to-day training schedule. I don't understand why people don't understand, when it comes to "anaerobic training", you just cannot be too precise about the approach on any given day--that's what Lydiard was talking about. He had a definite flow in his mind, when performing anaerobic training period, to gradually increase the intencity and volume. But he would never give you; without checking out how you're doing, as HRE indicated, by observing, asking, carefully monitoring; that "you should run fifteen 400m at your 5k pace" something like that. You have your bio-rhythm and that particular pace may be too fast on that particular day; may not be. You may finish the 12th one and it may hit you and you've had enough, etc. But simply because it's written that you're supposed to do 15, you'd go out and do 3 more... Then what would happen? Or would you prefer your athlete explicitly follow what you've prescribed?
Seriously, I don't mean to be derogatory but at the end of the day, Richard Tayler has the Commonwealth Games gold medal and most of non-believers don't.