A good example is; Ron Clarke, when he was a junior, tried to do 10 X 400m in 60 seconds every week in hopes to break 4 minutes for the mile; he never did. On the other hand, Peter Snell did 10 X 400m in 60 seconds in January of 1963. He went on and broke the world record for the mile. Same workout, same speed, totally different outcome. Think about it.
The fact that some of you are so addicted to Lydiard shouldn´t be the reason that in every post detail you profit the occasion to get Lydiard training up and be tendentious up to Lydiard.
Let me see things differently.
Different interval recovery leads to different output more than speed. If you omit the interval recovery of that 10X400m for 60secs we miss to understand what the meaning of that 10X400m is.
Ron is famous to be a 5000m 10000m specialist and not a 800m and miler as Peter Snell he was. Therefore Ron Clarke could show the effectiveness of that 10X400m for 60secs long term when he did break WRS in long distances, what he did after be senior age, because at that past decades, the 5000m and 10000m runs weren´t in the program of junior category.
In fact the same workouts can mean different relate to different middle distance or distance events.
Then you shall reformulate your comment as follows.
Peter Snell and Ron Clarke both did 10X400m in 60secs. Ron was able improved the 5000m WR from 13:35.0 to 13:16.6 and the 10000m WR from 28:18.8 to 27:39.4. That same workout results in Peter Snell mile WR.
Resume. 10X400m for 60secs is more effective for long distance runners than for milers.
You maight reformulate your comment. Or simply you can´t…