I learned a lot about nutrition and fueling by preparing for and running the Yeti 100 Mile Endurance Run. Everyone is unique, and different courses dictate different nutrition needs, but I’ve provided some guidelines that will help you best prepare for your race. Remember the adage “We are an experiment of one” when reading through these guidelines. What works for one person may not work as well for another. Testing your fueling plan during training is best, but always be prepared that race day may confront you with a new set of conditions.
The distance of an ultra is not always as important to consider, as much as the time that you will be out on the trails. For a technical 50k, you could be out in the woods through lunch and dinner. In ultras, one of the most important lessons is to eat early and eat often. It’s also wise to take a gel within 30 minutes of the start of a race. Then, continue to consume small amounts of nutrition about every 20-30 minutes.
Well trained athletes can burn up to 600-1000 calories per hour of exertion. However, our stomachs can only process about 200-400 calories/hour on the move. This number will vary based on the size of the runner, effort level, temperature, and how easy it is to process the food. A typical athlete can store glycogen to fuel the demands of 90 minutes or less of activity.
What types of foods to eat: the desire to consume food wanes the longer you are out on the trail. That said, the food that you craved at mile 20 might sound very different to you by mile 66. Conventional running fuel includes: gels, energy chews, sports bars, and sports drinks. Each of these products offer an option with caffeine and/or electrolytes. Gels are relatively easy for the body to digest. The type of sugar depends on how quickly the energy lasts over time. Sugars like honey act quickly but wear off fast as well. Maltodextrin offers a slower release of energy over a longer period of time. During a run, most of your calories will come from carbohydrates. Make sure to consume fluids with food so that absorption can be facilitated.
Aid station food can offer a good variety to the fuel that you packed in your drop bag (gels can get very old after hours of sucking on sugar). Be careful trying new things, and don’t rely on the aid station to have your favorite trail snacks. Examples of aid station fare include potatoes in salt, chips, m&ms, pie, brownies, soup, grilled cheese, peanut butter and jelly sandwich wedges, gatorade, and water.
I had stomach issues during the first ~half of the Yeti 100, and I’m not completely sure why. The best I can explain is that it may have been nerves. Either way, I knew that it was important to continue eating and drinking. Otherwise, I did not have any issues eating, but my desire for food started to diminish. Many runners experience nausea toward the end of the race (another reason to front load the calories if you can). Ginger chews and ginger ale are good remedies for an upset stomach.
Here is a troubleshooting table that may be helpful to share with your crew so they can help you if things start heading south:
Below is an example of the food that I had planned for the Yeti 100. I also had a lot of different kinds of food packed in a bin for my crew to have available just in case I craved an Oreo or a potato chip. I pumped/breastfed throughout the race, so I also calculated extra demand for calories to produce breastmilk. Toward the end of the race, the only things I could tolerate were Starbucks frappuccinos, Honey Stingers, and Cliff Shot Blocs.
There are a lot of running books that have complete chapters on fueling for an ultra. Here are a few books that I recommend:
Do you have any fun fueling stories? Experiences are the best way to learn!