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You may have heard of the saying “carb loading” but what is it? First off let’s talk about carbs first. Carbs, otherwise known as carbohydrates, are one of three macronutrients. Carbs are found in wheat, grains, beans, some vegetables, and other sources. There are different types of carbs. For simple terms, there are complex carbs and simple carbs.

Complex carbs are when they have a lot of fiber and are the whole grain of the plant, making it harder for the body to digest. This is a great thing as it keeps you feeling full longer. Plus it has a bunch of vitamins and minerals! You can think of simple carbs as there is not a lot to them. Meaning they can be digested really fast and are used for energy right away. They often don’t have a lot of fiber to slow down the digestion process. They can be found in sweetened foods or beverages, crackers, baked goods, and are considered added sugars. They come in multiple forms. Some examples of simple sugars are: glucose, fructose, lactose. One of the most popular added sugar ingredients that is found in processed foods is high fructose corn syrup. So it would be best to avoid foods with that ingredient.

The idea of carb loading is that it helps athletes perform at their best! “It makes sense that eating carbohydrate-rich foods to maximize our glycogen stores — a strategy known as carbohydrate loading — provides athletes with the energy necessary to sustain an increased level of physical activity for a longer duration” (Solga, 2019). Typically an athlete will carb load before a big meet or race. The amount of carbohydrates that are eaten totally depends on the type of athletes along with what sport they are in. A long distance track running will need a different amount of carbohydrates compared to a long distance swimmer.  “For example, an athlete can store 1,800 to 2,000 calories of fuel as glycogen in the muscles and liver. This energy can fuel about 90 to 120 minutes of vigorous activity. More recent evidence suggests that in events lasting longer than 90 minutes, maximized glycogen stores may improve a runner’s finish time by 2 – 3%. This could translate to a 5- to 7-minute improvement for a 4-hour marathoner” (Solga, 2019).

Since one of the big ideas of carb loading is to build up the stores of glycogen in the body to help during an event, a big question to ask is what happens when glycogen stores are depleted? Some endurance athletes such as runners experience a phenomenon called “hitting a wall” where their glycogen stores are fully depleted. What happens when endurance athletes hit their wall? Their performance goes down hill fast!

So what is the right way to do carb loading if wanting to avoid gastrointestinal discomfort? There are different types of ways to implement carb-loading. A classic approach is to go  through three days of glycogen-depleting phase that incorporates very high intensity workouts and very-low carbohydrate consumptions. After that, for the next three days of tapered physical activity with high-carbohydrate intake.

Carb loading may seem awesome however, there are some studies that show eating a high amount of carbs can actually have a negative effect on performance.  It is not optimal for all athletes and can increase risk for injury while training in a depleted state (Saolga, 2019). Some studies even show that trained athletes may achieve maximize glycogen stores without the need for a depletion phase in as little as 24 hours (Saolga, 2019). One of the biggest symptoms it can have is causing gastrointestinal distress. When leading up to a race / event an athlete should consume the same types of foods rather than switching it up and eating a large amount of carbs. In simplest terms don’t change anything when it comes to diet the day of the race / event or leading up to it!

Is Carbohydrate-Loading Right For You?

Unless you are wanting to become an endurance athlete and are looking to decrease your event time it is not necessary to do carbohydrate-loading. Carbohydrate-loading is not meant for people going to the gym everyday. However if you are into marathons and are looking to decrease your time and think about carbohydrate-loading make sure to talk to your doctor first! As carbohydrate-loading is not meant for all athletes it is not meant for all non athletes.