Lots of people ask how someone goes about training for a 100+ mile race. My thoughts on this are quite simple: You need to place equal value on both your physical and mental training. Everyone is different, but the best way I've found success in my training is to take a goal that may seem a little crazy at first (for example, the thought of running 30 miles by yourself on a Saturday morning), and repeat it enough times that it simply becomes the normal routine (eventually you find yourself run 30 miles with ease every Saturday).
Once you break through that mental wall of running 30 (or 50 or 100) miles the first time, you've taught yourself that it's not only achievable, but the more times you do it, the easier it will become. ...and everyone likes to go for easy runs, right? It's that simple.
Here's a current example of me applying this training method:
This spring I'll be running two 100 mile races as part of my 'Run 192' training. One of these races, the Massanutten Mountain 100 miler, qualified as "a little crazy" to me the first time I examined the course. Simply put, this is a 101.8 mile race over the worst possible footing I've ever seen. It's not that the rocks on this course are the biggest I've seen- it's actually quite the opposite: The majority of the course looks like someone took a normal hiking trail with large boulders and trees and then put them in a blender. Simply put, there are so many loose/jagged/annoying rocks on this course that if you try to pick your head up to enjoy the beautiful nature around you while running, you will quickly realize your face does not make the best braking device while sliding down the side of the mountain.
When you combine those trail conditions with the nearly 20,000 feet of elevation gain over the course, this race certainly requires special training to go from "crazy" to "normal" in my mind. That said, my training plan to prepare for this race is essentially the same training plan for someone attempting to run their first 10k road race: Get out on there and run the terrain often enough to make it the usual, comfortable routine.
To date I've made 4 training trips to run portions of the Massanutten course (I've run about 40 miles of the course thus far). That initial "No Way!" mental reaction I had when seeing the terrain for the first time has since been lowered to more of a "This isn't so bad, as long as I run in a football helmet" level of thought. After a few more trips out there, I'll have my brain drinking the "I LOVE this trail!" Kool-Aid completely. ...it's that simple! Now get out there and run!