In chapter 2 of "No Bugles, No Drums", Snell (1:44 800m PR)says this about training with Lydiard:
"I was deeply conscious of my shortcomings because a certain line of Arthur's advice was in my mind. It still sticks there today. He said that in his opinion when I got distance running under my belt so comfortably that I could run a hard Waiatarua and still feel like going round again - then I would be ready for anything in the world. Since the Waiatarua is a soul-searching 22-miler through the steep and densely bushed Waitakere Ranges, it seemed a remote and improbable objective in my initial distance-running days."
Then later in the book he describes his build-up to the Rome Olympics where he won gold in the 800.
"On Mayday I ran my first Waiatarua and the 2.5 hours it took me showed a great deal of promise."
"Murray, with whom I ran the Waiatarua fairly frequently at this time..."
"I did three weeks of hill training and noted that a pattern of performance was emerging in which, while my work during the week was spasmodic, I was able to knock out a good Waiatarua every weekend."
Later he says:
"With the Europe tour a certainty, I now dashed into another crash programme. My training had been patchy but I'd put in some solid runs round Waiatarua and I felt much better physically and mentally than I had two or three months earlier."
It is also noteworthy that the aformentioned "Murray", another Lydiard trained athlete won the 5000 at the 1960 Rome Olympics.
From "Run to the Top" by Lydiard:
He has a 5000m training schedule on pages 75-77. The Sunday workout is listed below:
"Sunday: Run twenty miles evenly at quarter-effort"
After 4 weeks of the tweny mile Sunday run, he then calls for his 5000m runners to "Run two hours evenly" each Sunday from weeks 5 through week 8.
I trust this increases your understanding of the Lydiard system.