So many 400 repeats with “x” rest as a rough idea for marathon pace?
I find that running 53 consecutive 800s give me a pretty good idea of my marathon time. YMMV though, and beyond that, it is often pretty hard to tell and very subjective at best.
found it, its 12*800 with 20 second walks as a ball park.
Yassou (sp?) 800’s.
there was some research a few years back that show your recent 10k time was an excellent marathon predictor. Multiple it by 4 and add some %.