Fueling for 50K

Updated: May 10

Dear Chaski(s),

Do you follow a special diet? What do you eat both during big blocks of training and during ultras?


Everyone I've ever met

Editor's note: This reply is a repost Chaski Coach Ty wrote a couple years back in the leadup to his attempt at the 50K World Record. The info is still great and the question is no less common, so enjoy!

One of the most popular questions that comes up whenever you tell someone you're a long distance runner is about diet. How do you fuel your body to cover 31+ miles on foot? How do you keep your body healthy while running 20+ miles every day in training? Whether you’re preparing for an ultra-marathon or just trying to get fit and eat a bit healthier, here are a few things I’ve learned that I hope might help.

Training Fuel

For starters, your caloric intake should be proportional to the amount of exercise you’re currently doing. If you’re running upwards of 70 miles per week, you will definitely need to eat more than you would if you were only running twice per week. Generally speaking, your body is a pretty good judge of hunger; it will let you know when it is craving additional energy, and when it is satisfied.

As nutrition is a very young science with constantly changing norms (and even now, plenty of contradictory ideas), it is recommendable to take all these suggestion with a grain of salt. The following is just what I do and what makes me feel good on a day-to-day basis. Also, none of these suggestions are cut-and-dry; I violate all of these “rules” from time to time.

As quoted in the cult-classic Once A Runner by John L. Parker, “if the furnace is hot enough, anything will burn, even Big Macs”. While you are a young runner, yes, you can probably eat anything that you want and get away with it; however, it is best to eat a somewhat balanced diet, based around whole grains, produce, healthy fats, and lean proteins.

Groceries from a normal shopping day at Casa Chaski in Quito, Ecuador

DO: eat produce. For instance, I personally strive to eat at least one (preferably two or more) servings of produce with every meal. When living in Ecuador, it is relatively easy to consume copious amounts of fruits and veggies, due to the availability and low cost-per-calorie. Some of my go-to foods are: banana and other tropical fruits with yogurt, broccoli and rice, carrot and beet soup… and pretty much any other food with color!

DON’T: rely on packaged foods. Additionally, I aim to avoid eating packaged foods — i.e. in general, I try to snack on things that didn’t come in a vacuum-sealed bag (think fruits, toast, etc.). Lastly, I steer away from foods with added sugar during a heavy training block. Although many sugar-dense foods are calorie rich (and I do burn plenty of calories each day), consuming high sugar desserts is not the most efficient way to refuel my body. Human bodies were not created to digest large amounts of sugar at once, so when I have a sugar craving (again, during a heavy training period), I first reach for a piece of fruit, as these natural sugars are easily digestible.

DO: eat food you like! All in all, I advise that you find nutritious foods that you like, and eat them on a regular basis! Eating certain foods is comparable to exercise, in that if you don’t like it, you will not stick with it. Just keep trying new foods until you find something that you enjoy!

Pre-Race Routine

The most important rule regarding race day fueling is: NEVER try anything new on race day. Always go with what you know!

DO: test your race-day fueling in practice.The most advisable thing to do is to test your pre-race meal before a workout or a long run. This way, you can see how certain foods affect your stomach while you’re running at an effort comparable to your upcoming race.

Before a long race, I try to eat a large, bland, carbohydrate-rich meal the night before; however, I never overeat to the point of uncomfortably full. The morning of, I eat according to my hunger levels, and never force feed myself. Sometimes I won’t eat anything solid, even before a marathon if my stomach doesn’t feel ready. Lastly, don’t forget to hydrate! You’ll use a lot of water — especially in a long race — even if it’s cold.

A perk of elite racing is the ability to have your own bottles out on the race course. Here are the hydration bottles that I used during the 50K World Championship!

So what do I do specifically? Throughout the day leading up to a marathon or 50K, I drink plenty of water. The evening before, I eat 2 packets of instant ramen noodles (about 800 calories and easy to transport and prepare in a hotel room) for dinner. The noodles are dense enough that I can eat a portion of this size without feeling sick to my stomach. If I’m still hungry before bed, I will snack on something bland — like animal crackers or pretzels. To help me fall asleep at a decent hour, I will sip a cup of Sleepytime tea.