I’m training for an ultra – I’m doing some long runs and some short fast runs. The short fast runs are far more difficult than the long runs. I doubt the long runs do anything other than get my head used ot being on my feet for hours on end.

Same sort of thing I’m aiming for too. The head side of long distance shouldn’t be underestimated – how to manage thoughts, pain, pacing, variations in terrain, navigation, stopping technique getting ragged – all whilst tired. And the side to ultra-distance which most forget at first: learning how you burn up energy and when, how and how much fuel to take on board.

surfer, I’m not fixated on his army training, I’m suggesting his training consisted of more than interval training. I don’t think world class distance runners thrive on interval training alone. Sure, they’re beneficial sessions, e.g. mile reps at altitude as per Mo, but as a training method alone? Hm!

I’m suggesting his training consisted of more than interval training.

But from what I have read this is exactly the case. Are you able to point to anything that claims differently? If not why would you suggest it?

I don’t think world class distance runners thrive on interval training alone

See above. And its pretty accepted that they do. There are reasons why athletes dont do what Zatopek apparently did but that doesn’t detract from their effectiveness.

but as a training method alone? Hm!

Again, see above. Bear in mind that with a warm up and down and a session of 40 x 400 (and unless these are very intense which I dont think they were (relatively!)) Zatopek was likely jogging inbetween. I only say that as its typical of a fit distance runner to jog slowly between reps.