In my opinion, there’s three big challenges in running a hundred miles. I’m going to ignore fitness when talking about challenges though. There’s a base level of endurance competence that you need to bring to the table. If all you’ve ever done are 5Ks or day hikes, you’ve no chance of moving your body 100 miles. Once you have built up that base though, there will be three big challenges you need to overcome if you hope to earn your buckle:

  • Mile 60 Mental Wall
  • Nutrition
  • Environmental Conditions

Mile 60 Mental Wall

Let’s start with the one that took me out of my first hundred. Somewhere in the 60-70 mile range, you’ll hit the mental wall. At this point, you’ve gone a very long distance. Things hurt. It’s dark out. Depending on the course profile, you could be staring at another 10-15 hours left before you will finish. And that will seem like an impossibly far distance. Like three times as far as you’ve already traveled. Frankly, a distance you won’t want to cover. At this point, your mind will do everything possible to get you to stop. It’ll have you focus on your pain or discomfort. It’ll bring back all those failed training runs and convince you you’re not fit enough for this. All your demons and insecurities will come out to play in your head. You’ll think of a thousand things you would rather be doing and one thing you really want to stop doing.

At this point you have a couple options. Some people will have a mantra or bit of motivation they will say to them over and over again to keep themselves going. This works for some as it will reinforce why they signed up to do this in the first place. My trick is to not think further than the next aid station. Forty miles may be an impossibly far distance, but anyone who can run 60 miles can shuffle along for another 5 miles. And then another six miles to the aid station after that. Do that a couple more times and you’ve got your hundred mile finish.


The traditional nutrition advice always cracks me up: train your gut on your long runs. It’s the type of advice that sounds great until you actually try putting it into practice. For example, I can eat an Oreo every 15 minutes for four hours, but there’s zero chance I can do that for a hundred miles. The fallacy is that what will work for 4-6 hours will continue working for 30 plus. I’ve found that my stomach can stomach the same thing for up to eight straight hours. You’ll need to stay flexible and be prepared to move on to Plan B when your long run tried and true Plan A stops working. And then on to plans J and K before you’re finally done.

The interesting thing about nutrition during hundreds is it’s completely different than how we fuel our bodies in day-to-day life. During the race, you’ll need an IV steady drip of 200-300 calories every hour. Outside of races we dump 800 calories into our stomach, let it digest for a couple hours, and then take a couple hour break from eating before starting the process all over again. Our stomachs just aren’t used to working continuously for over a day straight. While you could try to replicate this in everyday life, in reality you won’t be able to really train your gut outside of races.

I have two fueling strategies that I use that work well for me. The first is to get as many calories in via liquids as possible. That’s why I always carry soda in at least one of my bottles. I typically don’t use the sports drinks as they have about half the calories as Coke or Mountain Dew. You lose some electrolytes with this method so I supplement with salt pills when its hot out.

My second hack is what I call my Seven Flavors strategy. It’s simply to always be rotating through seven different flavors of food and fluids. The thought process here is that you’ll eventually get tired of ingesting one or two things, but seven is enough variety to keep your stomach happy enough to continue working for a little bit longer (seriously, I promise, just a couple more mouthfuls are coming your way!). I’ll also try to mix up between salty and sweet foods as I go along. Some people swear by solid foods, but that rarely seems to appeal to me in aid stations. The key takeaway here should be to eat whatever looks most appetizing even if that’s just “meh”. I’ve finished hundreds eating a gel every three miles (not recommended). I’ve also finished races just eating orange slices and drinking Coke (also not recommended). It really doesn’t matter what you’re eating as long as you continue to get your calories down.

Environmental Conditions

Heat, cold, rain, altitude. These will end your race faster than you can imagine. The challenge here is similar to nutrition above in that what works for 4-5 hours may not work for 10-20 hours so it’s difficult to simulate this in training. Take cold conditions for instance. I’m sure you’ll have your kit dialed in for 40 degree temperatures, however that’s likely while running. Your body will react differently to 40 degrees in the middle of the night 15 hours into your race when you’re moving much, much (much) slower than your training runs. My guidance is to always dress like it’s 10-15 degrees colder than it actually is because that’s what it’ll feel like. Also, I have never, ever been too hot overnight in a hundred even during summer races.

Rain’s probably the worst thing to run in. An hour or two isn’t that bad. Four hours of a steady rain is about the point where I start questioning my life choices though. No matter what type of gear you have, you’re going to be wet. The goal shouldn’t be to stay dry, but to stay warm. The longer it rains, the more you need to focus on staying warm even in temperatures above 50 degrees. Changing into dry clothes helps. Drinking hot liquids/foods helps. Not thinking about how much longer it’s going to rain can also help. Thinking about your warm, dry bed does not help.

It should go without saying, but weather can also be fickle and hard to predict. So just because Accuweather has a forecast out there doesn’t mean those are the weather conditions that you’ll experience. Plan for it to be colder and hotter. Plan for that 10% chance of rain to be a six hour downpour. You’ve spent a lot of time and effort to run 100 miles so don’t let “maybe” weather take you out.

The Dreaded Combo Platter

Even if you’re able to handle each of these challenges individually, they tend to interact and magnify each other. People typically have more nutrition issues when it’s hot out and blood is diverted from the stomach. Guess how hard it is to continue running after 60 miles and 5 hours of steady rain? And I didn’t even make it to sixty miles when I tried racing at altitude.

Once you “master” these challenges of running a hundred miles, the real fun begins. It’s time to talk about the nuances you’ll encounter. . .