Certainly no expert here and am only starting to scratch the surface of this topic myself. Enjoyed ‘How bad do you want it’ and am not far off finishing ‘Endure’ - both really good and insightful in their own ways and definitely worth reading/listening to both.
There are also a few really good tips in the ‘Ask a cycling coach’ podcast and a few episodes specifically dedicated to the topic in the ‘That Triathlon Show’ podcast that are well worth a listen as well.
The one thing i’ve found that really worked for me and is something that I use when the going gets tough in races and even in training (specifically thinking of the Disaster day as an example) comes down to motivation/purpose; i’ve heard a lot about people being able to do more and go harder when they are doing it for someone/something else, rather than themselves.
Dloves example above relates exactly to this point and it helped him to the finish line with a broken foot. My own experiences are nowhere near that level but I first applied it during a half marathon I ran for charity. Towards the end when the going got harder I was putting myself in the shoes of the homeless which was the cause I was supporting. I don’t know what it is like to be homeless but I can imagine that having to spend a night on the streets is terrifying and you hear/see stories of drunk people on nights out beating up and humiliating the homeless which disgusts me. I found that when I really started thinking about this that my own pain/suffering during the race was quite insignificant and really was a first world problem that i was then able to ignore and push through much easier than I might have done were I just running for myself.
In subsequent events where there was no charity involved I used my daughter as motivation to help me through the tougher times; she’s only 2 and won’t remember any of this at this stage but in my head me pushing through demonstrates to her life lessons such as hard work, not taking shortcuts, dedication and determination etc. I visualise her at the finish watching her dad cross the line and in the process learning a little more about how to be the best she can be.
By doing it for someone else my perception of effort was reduced and the amount of pain/suffering I was prepared to tolerate increased quite significantly so I would definitely recommend experimenting with this kind of thing in your training in the lead up to the event.