Nutrition / Food

How Many Carbs Do Runners Need?

Carbo-loading is common among runners. Experts weigh in on when it is and isn't necessary.

A bowl of pasta the night before a race? Yep, we’ve all heard that one before. In fact, carbo-loading is as synonymous with running, as eating protein is to weight lifting. But before you go ordering a second helping of spaghetti the night before your big race, take a peek at what our experts say about how carbohydrates affect runners.

Why are carbs important?

Think of carbs as the gas necessary to run your engine of a body. You wouldn’t start a road trip without filling up first. So, why on earth would you take off for a 10K without proper fuel?

Once you’ve got all the fuel you need, start training for your next race with Aaptiv.

“Carbohydrates are one of the three macronutrients [that serve as] the main fuel sources [that] our bodies [need to] burn for energy during physical exertion,” explains Danielle Stadelman, RDN. But, not only are carbs burned for immediate energy, they can also be stored in our liver and muscles as glycogen. This prevents the body from breaking down protein for fuel. Translation: carbs have the ability to give both short and long-term energy.

Are all carbs equal?

Carbs come in all different forms. Many times, they’re labeled “good” or “bad.” However, let’s be honest, the designation between the two can get a little murky. Instead of thinking of carbs in terms of right and wrong, think of them as “complex” and “simple” (note: you’ll also hear these referred to as “whole” and “refined”), explains Lori Zanini, RD, CDE, and creator of For The Love of Diabetes.

The primary difference between these two is how the body digests them. Complex carbs are digested slowly and contain larger quantities of fiber, vitamins, and minerals. These can include whole fruit, vegetables, whole grains, beans, nuts, and seeds.

Conversely, simple carbs refer to those that are digested quickly and contain minimal fiber and other nutrients, which can upset blood sugar levels. You find these types of carbs in sugary beverages, refined grains (such as white bread and white rice), sweet desserts, processed foods, etc.

“Carbohydrates are an athlete’s rocket fuel for best performance,” says Stadelman. Because they’re essential for training, she suggests getting in a habit of including whole carbohydrate-rich foods, such as sweet potatoes, whole fruits, or whole grains, along with some lean protein and healthy fats in all of your meals and in most of your snacks.

“This will help replenish your glycogen stores daily so [that] your body can train harder and smarter,” she says. And, surprise, surprise—limiting refined, simple carbohydrates is key, she says. “These carbs provide energy, but don’t nourish the body with vitamins and minerals, unless fortified,” she adds.

So, how many carbs do runners really need?

Just as every runner’s specific training needs are unique, their dietary needs differ, as well. However, in general, it’s a good idea to keep the recommended dietary allowance for carbs in mind as a base. Because 45 to 65 percent of your daily calories should come from carbohydrates, the general rule is to consume 130 grams per day, explains Stadelman. However, many runners require more than this minimum, she adds.

Just as all runners require different amounts of carbs, they also require different types of training. At Aaptiv, there’s something for everyone.  

“As a runner, if you train hard, a daily carb intake of about 2.3 to 5.5 grams of carbs, per pound [of] body weight prevents glycogen depletion, and not only allows you to train harder, but also compete at your best,” she says.

Can you break that down a bit more?

Stadelman explains that if a runner weighs 150 pounds and only runs a few times weekly, their daily carb intake should be about 2.3 grams of carbs, per pound of body weight. This means they would need about 345 grams of carbs each day.

“Runners should understand that as training frequency, time, and/or intensity increases, so should their carbohydrate intake, in order to properly fuel and refuel worked muscles,” explains Zanini. Spread your carb intake out as evenly as possible to maximize energy available to muscles, she adds.

What should runners do before a race?

If you’re wondering if you should carb-load, the answer is both yes and no. Eating a larger portion of carbs can help increase the number of glycogen stores that are available during exercise. But do it smartly, says Zanini.

“‘Carbohydrate loading’ the night before is often ineffective if done in isolation,” Zanini explains. “Instead, athletes should aim to slightly increase their carbohydrate intake gradually, over the course of a few days, to best maximize glycogen stores and be able to perform at higher intensities, over longer periods of time,” she adds.

If you’re prepping for an event that’s under 90 minutes in duration, Stadelman says you’ll likely be alright with your normal carb intake. However, once you hit that 90-minute mark, your body requires a bit more rocket fuel to beat the wall. “Your diet should be carbohydrate-based. However, it must also be balanced with healthy fats and adequate protein to prevent muscle breakdown and also support muscle repairs,” she says. “Carbo-loading won’t make you run faster, but it may help you perform longer before getting tired,” she adds.

Time it just right.

Just be careful not to eat too much. “Eating too much could actually backfire, leading to GI discomfort and hindering performance,” says Stadelman. “The golden rule to follow is never try anything new on race day—and this also applies to carbo-loading.”

Instead, Zanini says that the night before a morning race, consume a moderate meal at least ten to 12 hours beforehand to allow for plenty of digestion time. And don’t forget to fuel up during longer activities, such as a half marathon or marathon.

Runners should consume 30 to 60 grams of carbohydrates per hour, during exercise. This can be in the form of things like gels, sports drinks, and bananas. This is an effective way to sustain performance and prevent glycogen depletion, says Zanini.

Lastly, don’t forget to fuel up with carbs post-run, too. “Similarly, consuming a high carbohydrate meal or snack within 30 minutes to an hour after exercise is [the] best to refuel properly,” she says. In this case, reach for a “simpler” carb in order to more rapidly fuel or refuel worked muscles!

Along with proper nutrition, cross training is also important for runners to build strength and improve pace. Luckily, Aaptiv can help.

Food Nutrition


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