Darcy AfricaSince the equine nonfeasance of 1974 we’ve had 39 years of nutrition science to try and figure out what the best strategy for fueling a 100 mile race is. From the early days of double fisting a plastic bear-shaped honey bottle in one hand and a glass bottle of apple juice in the other, we haven’t actually come that far. Stomach issues are either the biggest cause of, or the most convenient excuse for DNF’ing. Either way, one thing is clear—fueling a 100 mile race is tough.


Some talented runners fall well short of their expectations on race day simply because their stomachs aren’t up for the 12 to 48 hours of sloshing digestion required. Environmental conditions are also a factor. When the temperature or the altitude are drastically different than what an athlete is accustomed to, it inevitably plays an outsized role in their stomach’s demise.


What we can control however is what we eat and drink. First Endurance sponsors some of the very best 100 miler runners out there, record holders and champions among them. Using these athletes as my resource I attempted to draw out any commonalities that might be universally applicable, or at least a great starting point for the rest of us.


Have a Plan
First Endurance ultrarunners universally had nutrition plans going into their 100 mile races. Duncan Callahan told me, “I write it out so my crew and I both know I want x amount of calories, liquid, and salt per hour as a guideline. As well as what I intend to grab at aid stations or what I plan to carry for the next section.”


Like Duncan, most wrote their intentions out. The obvious exception being Karl “100 miles ain’t that far” Meltzer, who said, “I have a plan, and use it to fill my drop bags, but really, it’s impossible to know what a runner really wants late in a race.”


LukeNelson_croppedHaving a plan will help you stay on track, even when your mind and stomach are telling you that you are done. Knowing exactly what you want will also quicken your pace through aid stations, not to mention make life easier on your crew. With that said, each runner stressed the importance of being flexible as well. There are simply too many variables to manage during a 100 miler to be too rigid. Something is going to go wrong, or off script, and it’s how you respond to this that matters most.


Gel Works

There are a lot of options for what exactly to eat on the trail. Some of the most popular options include; carbohydrate powders mixed in your water bottles, energy bars, pureed baby food, trail mix, energy gels, or even real food. When asked what they actually consume while racing, each and every athlete had gel as a major part of their nutritional strategy. This makes good sense, as gels are easy to carry and easy to digest, giving runners quick carbohydrate energy.


Front Load

Interestly, most of the athletes acknowledge the fact that their ability to take in calories withers as the race goes on. Dylan Bowman said, “Eat more earlier in the race to proactively account for the inevitable lack of appetite in the last thirty miles.”


When their stomachs were in good shape, the athletes tended to eat a few more calories. The longer the race, the more likely you are to have stomach issues. If you know your stomach won’t be functioning properly in the late stages of a race, having a loose guideline to eat well, but within your tolerance level seems like a good strategy. Overeating will of course works itself out, but will inevitably slow you down.


Use Cautious Bonk Recovery

Bonking is when your body simply runs out of calories for energy. A well trained athlete can store about 90 minutes of glycogen fuel in their muscles and liver. Obviously, this isn’t enough to get through a 100 mile race, so we are forced to eat while we run. If you fall behind forget for an hour, or fall behind, you end up bottoming out. If you run ultras this has likely happened to you many times.


The good news is a 100 miles is a long way, so you have time to recover. Getting instant sugar is the key. Krissy Moehl said, “I’ve found that if I am low and am trying to come back it is best to take sips off of the EFS liquid shot flask more frequently until I’m feeling better.”


You’ll be inclined of course to lift the aid station table off the ground to dump it’s contents into your mouth. This isn’t the best strategy (trust me I’ve done it). Even though you don’t have the proper glucose to think straight you must fight the urge to overeat in this situation. That will lead and either throwing up or not being able to move because all the blood in your body has now been diverted to your stomach for digestion.


 As an interesting side note: I had the athletes rate their stomachs on a scale of one to ten, with ten being they could eat rocks and it wouldn’t upset their stomachs. Surprisingly, all six athletes rated themselves an eight out of ten. There are many factors to becoming a successful 100 mile ultrarunner, maybe one is being genetically gifted with the ability to eat on the run. My hunch is these athletes have trained themselves and refined their strategies over time through trial and error. Hopefully, this can be your starting point to future ultra success. 


Visit our nutrition for runners page for detailed nutrition plans.