Mental toughness vs. physical ability

I also think that the 20 mile wall is a stupid obstacle that some idiot invented that has done nothing but hurt hundreds of thousands of runners. If we instructed runners how they will feel when they get to that point in the race, I think it would go away. Once I figured that out(after 3 marathons), I have never had an issue with it again.

You know it's not fuel because runners hit it, regardless of how long they have been running. You see it in 2:30 hour marathoners and 5 hour marathoners who have consumed much more fuel than the faster runners. That's where I'm inclined to go with Tim Noakes' Central Governor theory. If you prepare for how you might feel at mile 20, it's much easier to push through that. Brain Power!!!

On that note, I'd be curious to see if the "20 mile wall" is just as prevalent in runners who do a lot of progression (HARD last 2-3 miles of a mid-week run) or fast-finish long runs during training. Seems like those are built just for the purpose of preparing the mind to overcome fatigue and squeeze out those last 6.2 miles on pace.

Mike I would agree with that. The second half of my last cycle I started finishing my long runs very strong because the marathon I was to run had a nasty hill to finish and I wanted to be prepared for that. As it turns out those last six miles of the marathon were the strongest I've felt of the marathons I've run. My fastest mile came within those last six. I have to believe that was a reason.

Mike MacLellan wrote:On that note, I'd be curious to see if the "20 mile wall" is just as prevalent in runners who do a lot of progression (HARD last 2-3 miles of a mid-week run) or fast-finish long runs during training. Seems like those are built just for the purpose of preparing the mind to overcome fatigue and squeeze out those last 6.2 miles on pace.

I would say since I started running more consistently, added miles and the type of workouts you mentioned above the wall has been moved back for me. Although you have to keep in mind that you also have to be good about your fueling leading up to the race and during the race. Also I feel that heat changes things a lot and you have to be even more on top of fueling of your fueling needs.
As far as the training aspect goes I have really pushed that wall back. Now to be honest maybe I'm starting to still hit the Wall around 20 but I really don't notice because of my mental toughness. I would say on normally now out of my last 4 marathons I would say that I will start to feel the wall or fatigue around mile 24-25 compared to 18-20 when I first started. Now that I'm hitting that way so much later it is a lot easier to pull from my mental toughness due to the fact I guess it sure is a lot easier to gut it out for 2 miles then it is 8 miles.