After months of training, you want your race to go as smoothly as possible: good weather, fresh legs, and plenty of energy. While you cannot control the weather, you can control your energy and prevent yourself from bonking. Eating carbohydrates during the race can help your energy stay high and keep you from hitting the dreaded wall. Eating while running may sound difficult or confusing, but it does not have to be. Here’s how to fuel on race day, so that the wall doesn’t derail your hard work. 

When do I need to fuel during a race?

Most runners will not need to take fuel during a 5K or a 10K race. These races are so short that you will not burn through your carbohydrate stores, especially if you eat a pre-race meal. However, once a race lasts longer than 75 minutes, you want to take fuel during the race. For most runners, this means you need to fuel during the longer races–including the popular marathon and half marathon distances. 

Why is race day fueling important?

Race day fueling is important because of how the body produces energy. When you run a marathon or half marathon, your body uses the aerobic metabolism of carbohydrates to produce energy. Aerobic means ‘using oxygen,’ and metabolism is your body’s process of changing fuel into energy. So, aerobic metabolism of carbohydrates means that your body is using oxygen to break carbohydrates down into energy. 

Carbohydrates are stored in your muscles (glycogen) and available in your bloodstream from the food you eat (glucose). Your body only has so much stored glycogen; once you run for more than approximately 90 minutes, you begin to run out of glycogen. So, to keep producing energy so that you can keep running, you also want to have glucose. 

A pre-race meal with carbohydrates will provide some glucose. However, when you are running for 90 minutes or longer, you need more carbohydrates. Taking in easily digestible carbohydrates gives your body enough fuel to produce steady energy throughout the race. Without this energy, you will feel fatigued and slow down. If you fuel during your race, you can keep pushing yourself. 

Fueling is critical in the marathon. When you are running for two hours or longer, your body uses a large number of carbohydrates for energy. If you do not have enough, you risk hitting the dreaded wall around mile 20 and struggling through the final 10K of the race. Fueling can help prevent you from hitting the wall. 

What types of fuel should I take?

Man drinking water, fueling on race day, running nutrition

Since your body needs glucose to quickly produce energy, you want to choose a fuel that contains glucose. Glucose comes in the form of easily digestible carbohydrates. Specially formulated sports nutrition products, such as gels, chews, and sports drinks, contain glucose and other easily digestible carbs. 

Gels, chews, and drinks are also easy to eat while running. An ideal race day fuel should not involve a lot of chewing since you will be running simultaneously as eating. Other easy-to-eat, high-carbohydrate options include gummy candy, dried fruit, stroopwafels, and graham crackers.

You want to avoid high-fat and high-protein foods. These will not easily be converted into energy, so you will not get the energy boost you need. Plus, high-fat, high-protein and high-fiber foods are slower to digest, which means they are more likely to cause an upset stomach such as cramping or the runner’s trots. 

How to fuel on race day

For race day fuel to be effective, you need to eat enough of it. Do not wait until your energy feels low during the race. It takes about 10-15 minutes for a sports nutrition product to hit your bloodstream, so you want to start taking your fuel early into the race. Ideally, you want to take your fuel every 30-40 minutes during the race–starting at the first 30-40 minutes into the race. 

Taking your fuel every 30-40 minutes ensures both a continuous delivery of energy and that you get enough carbohydrates. You want to aim for about 30-60 grams of carbs per hour; the longer the race, the more you will need. A study published in the International Journal of Sport Nutrition and Exercise Metabolism found that marathoners who took 60 grams of carbohydrate per hour during the race finished an average of 11 minutes faster than those who did not. 

Taking a gel or chews every 30-40 minutes ends up being a large quantity of fuel. A helpful strategy can be to vary both the flavor and the form. You can alternate between chews and gels, for example. 

One common adage in running is nothing new on race day; that also applies to race day fueling! You want to practice your fueling strategy on your long runs throughout training to know how your stomach reacts.