Carb Loading For Runners: Common Mistakes And How To Do It Right

Carb Loading For Runners: Common Mistakes And How To Do It Right

Carb loading is something runners take seriously. Because carbs are a common fuel for runners, they are often a source of addiction. However, not all carbs are created equally. Also, many runners load up on carbs on a daily basis which is often unnecessary.

Many runners start running in the hopes of losing weight. Did you know that many people new to distance running actually gain weight, because they come home with the “run-gries” and actually eat far more calories than they possibly could have burned on the run?

The misconception that all runners need tons of carbs, and the overestimation of how many calories an average run will burn to cause many problems for some runners.

Carbs are very important as a fuel for runners when used correctly, in the right quantities, and at the proper time.

Pre-race Carb Load

Many marathons and half-marathons offer a pre-race pasta dinner because having a healthy store of carbs is a key component to having the energy to go the distance. Fueling a body to run 13.1 or 26.2 requires a lot of energy, and carbs are a great way to give the body that much needed energy.


When you consume a bunch of carbs, be it pasta, bread or potatoes, those carbs fill your body with glycogen. Science tells us that extra glycogen is needed for running more than 90 minutes.

When to Start Carb Loading

Conventional wisdom tells runners to start carb loading two to three days prior to a big race. A runner should take in 75-80 of their daily intake through carbohydrates in the few days preceding the race. Also, the runner should be sure these carbs are easy to digest.

What does that mean? It means that while the pasta is a great carb load, fatty Alfredo sauce is not. Nor is a marinara sauce with Italian sausage. Think of carbs that can be paired with lean meats and little fat.

Some runners make the mistake of eating a ton of carbs for the evening meal the night prior to a race. Actually, it makes far more sense to eat a larger, carb-heavy meal in the afternoon, then follow up with an easy to digest, carb-rich, but a smaller meal that evening.

Follow that up with good, carb-heavy breakfast about three hours before the race and you are ready to hit the pavement!

Changes On the Scale

Expect the scale to creep up between two and four pounds in the days before a big race. This is because as you carb load and increases your glycogen, your body will also retain water.

Know that this is not real weight and is not a cause for concern.

Carbs During the Race

Some people can go the distance without taking in fuel during the race; however, for races lasting over 90 minutes, most athletes need some carbohydrates. This can take the form of common runner carbs, which come in easy to consume gels, chews or beverages.

Other runners choose more non-conventional items such as fruit snacks (yes the kind little kids pack in their lunch). Far less common are runners who use real food items for race fuel. An item such as chunks of potatoes or bread with nut butter spreads is popular among some runners – in particular, ultra marathoners.

These carbs are necessary to avoid hitting the dreaded wall while racing. In addition to determining how much fuel you need as a you must also figure out which foods agree with your gastro system.

Some runners have a gut of steel. Other runners have sensitive stomachs and need to be very careful what they consume both pre and during their run.


For some, the distance they intend to travel comes into play. For example, many runners can run three or four miles after pretty much any meal. For longer runs the pre-run meal is more important.

All runners are not created equal in regards to fuel. Some runners are lucky and can eat almost anything before running. Also, some athletes can use a multitude of different fuels. It is not a one size fits all decision.

How to Carb Load

The first rule of thumb for carb-loading is to practice what you intend to do on race day. Conventional wisdom dictates that runners use whatever fuel they intend to use on race day for the last three or four long runs.

This does not necessarily include replicating the few days of pre-race carb-loading but does include the intended race morning breakfast, routine, and fueling practice during the long run.

The last thing a runner wants to experience is gastro distress during a goal race!

Stay Away From Fiber

Fiber is a healthy addition to your diet; but, pre-race or during your workout, fiber is the enemy. When looking to add carbohydrates to your diet, avoid fiber-rich items such as apples, peaches or pears.

Of course, you can peel the fruit to lessen the fiber. Fiber during a run can cause stomach issues or, even worse, the much-dreaded runner’s trots!

Carb Loading for Gluten-Free Athletes

Carb loading is pretty simple for those who can eat white bread and pasta. What about athletes with celiacs or who have to avoid gluten for other dietary reasons? Or athletes who simply choose to eat food in its most natural form whenever possible?


Some great natural carbohydrates are rice, potatoes, sweet potatoes, quinoa, and oats. There are also many gluten-free alternatives to foods mentioned above, such as bread, rolls, and pasta; but there are many choices in food that come directly from nature!

Just the Facts

So the conclusion? Carbs are important, but running does not give you carte blanche to eat cookies and cake in huge quantities on a daily basis. Paired with good nutrition, running is a healthy habit. Consuming carbs in normal quantities will help fuel normal, day to day activities and exercise such as running.

Races 90 minutes or longer certainly require some carb intake, in order to maximize performance. Athletes should up the healthy carb intake two to three days prior to distance races and should practice that intake increase for long runs.

Carb loading properly will help you to have a successful run if done properly. Eat right to run well, friends!