Ultrarunning: Keeping Up Your Energy with the Right Fuel

January 31, 2012

This article is part of Endurance Planet’s ultrarunning article series. If you have questions, comments or feedback about “Keeping Up Your Energy with the Right Fuel”, please leave it below in the comments section…

It is a given that to successfully accomplish an ultramarathon you need to fuel up with the right food and drink. All those calories you’re going to be spending out there on the trail or road will have to come from somewhere and will constantly need to be replaced. This is why most training guidelines that pertain to ultras advise testing and incorporating your fuel system in your long run sessions. It’s a preparation that’s as basic as all your other training routines. No matter how tough or fast you’ve made your body, you simply can’t run all those miles on an empty stomach.

Types and proportions

Most sports nutritionists agree that carbohydrates are the one type of nutrient that athletes are going to rely on heavily for energy. This is one of the body’s easy sources for glucose that fuels cell, tissue, and organ function. There are actually various classifications of carbs but the lay man version simplifies this into two general groups – simple and complex. The main difference is that the former is more easily broken down and absorbed while the latter doles out the carb energy across a longer period. The amount of calories you’re going to need to run an ultra is such that, simple or complex, you’re going to need all the carbs you can get. Their different effects though may imply particular ways to use each type to full advantage.

While majority of what you’ll fuel up on are carbs, you’re still going to need some fat and protein input. Various combinations of the three nutrients have been recommended such as the popular 40 (carbs) – 30 (fat) – 30 (protein) proportions. Some veteran ultrarunners however have said that a greater percentage of carbs, around 70 is probably more useful given the energy requirements of the sport. Whether you choose to take all three through energy products like sports drinks or from various sources of standard food are ultimately up to you. There are other considerations after all such as ease of preparation, portability, taste, and possibility of stomach upsets.

Before the race

Despite the common occurrence of pre-race loss of appetite possibly due to excitement or nervousness, most endurance athletes consider loading up before a race good practice. It makes sense to set yourself on the starting line with a full tank of fuel to get you through the first few miles. In this situation, experienced ultrarunners have often recommended complex carbs. Because they are more slowly digested and absorbed, they can in effect provide sustenance for a longer period of time.

While running

Once you’re in the middle of the race, the choices can become more variable. If it happens that you can only take in food between hours-long intervals then you might want to stick with complex carbohydrates. But if you have a system that allows you to refuel more frequently, then perhaps simple carbs such as the sugars found in power drinks would do. With the frequency, you may be able to avoid the “sugar blues” effect or the rebounding drop in blood sugar that comes after the rush caused by such easily absorbed sugars. One thing that most experienced ultrarunners note is that if you come to a point where you’re already feeling quite weak or your stomach’s complaining then you may have set your refueling points too far apart.


Do you have questions about energy and fuel for ultrarunners, or what you’ve read so far? Do you have any ultrarunning pointers of your own to add? Please leave your feedback, comments and questions below, and we promise we’ll respond.

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