Just read something in moores book on Bowerman. He had one guy do 100 200s am at 35 pace then 50 400s pm. That is 100 laps. 25 miles. He was copying Milhaly Igloi I remember that name. Hungarian. Crazy!!!!
My 8x100 is about about the pace of one of your 800's. I just have to do what I can do but that is impressive workout for sure.
There was a guy who followed the Norpoth system. They'd do 100X100. 50 and then lie down for a while then do another 50.
Most I've done is 24-30
So 8 is not intimidating.