I found this article this morning, apparently it was written by Ron Clarke back in 1995.
Quote:
"Frankly, we didn’t run all that far each day and I can testify that most of it was not too slow either. Our basic day-in day-out work out was 8 to 10 laps on the grass at Caulfield racecourse. At that time (not so recently unfortunately) the grass was beautiful – smooth and even and where we ran about 25 metres in from the fence (often barefooted), the distance of each lap was 1 ¼ miles plus 100 yards – around two kilometres – so we covered 16 to 20 kilometres each evening most, if not every week day, 50 or so weeks in the years.
But it wasn’t slow. We used to get faster and faster as the session progressed with very few still in the front pack by the end of the evening – certainly we were flowing along at better than a 5 minute mile pace, probably closer to 4.40 or even 4.30 each mile for the last 5 or 6 kilometres.
Our long Sunday runs may have been reasonably slow (around 5 minute mile pace) but within them were some hell-for-leather sprints along creek-side paths and really, really tough hills which we all attacked in good humoured rivalry."
http://blogs.teamtbb.com/mathieuohalloran/2012/03/14/the-myth-of-long-slow-running-by-ron-clarke/