I just picked any distance for ultra’s - but doesn’t matter what distance. I was just wondering, in general, how long do people build up to for their long run in preparing for those really long races. I would think due to injury risk and recovery they can’t get anywhere near the actual distance, but it is even half? Do they go into a 100k race and their longest run is 50k (which is horrendous), so they have no idea what the next 50k will feel like? What is that like then? I’m thinking about with marathon programs and people “hit the wall”, where is “the wall” for an ultra and how long do you suffer? Is it like 4 hours of going easy then another 4 hours (or more) of suffering?