The Wall and Carbo-loading

The marathoner’s worst enemy is not the runner ahead of them or even the upcoming hill – it’s the dreaded wall. We’ve all heard of it. It’s every runner’s nightmare. The wall is that feeling of being so completely out of gas that you can’t take another step. Some literally describe it as if there was a wall stopping them from forward movement – hence, the name. 

In scientific terms, the wall is when muscle glycogen stores become too low. Think of muscle glycogen as easily accessible energy. Carbohydrates are stored in the liver, blood, and muscle. The carbohydrates in muscles are easily used and readily available since they’re so close to what is using energy (our muscles).

The Low Down on Carbs

In recent years, carbs have gotten a bad rap. With the media constantly advertising no-carb/low-carb diets, it’s no wonder many people believe that carbohydrates are bad for us. However, they actually play a vital role in our health. According to the RDA (Recommended Dietary Allowance), about 45-65% of our calories should come from carbohydrates. Below are a few roles that carbohydrates play in our everyday lives.


  • Are the body’s main source of energy
  • Can be easily used for energy
  • Have a 2 x faster energy transfer in comparison to fats or proteins
  • Are needed for the central nervous system to function properly
  • Are good for intestinal health (some types of carbs are fiber)

Probably the most important role that carbohydrates play is that they are needed for our brain. Although it only needs a small amount, carbohydrates are vital for the brain to function properly.

How to Prevent Hitting the Wall


Many people refer to hitting the wall during a marathon as being unavoidable, but is it really? How do ultramarathoners and Ironman athletes manage to race for 24 hours, sometimes even longer?



When most people think of carbo-loading they imagine a gargantuan feast of pasta and bread on the eve of race day. However, this might not be the best idea in order to have your optimal race.

There are two typical ways to carbo-load – by gorging or nibbling. Gorging (supercompensation) involves eating a large amount of carbohydrates in a very short amount of time. Nibbling (moderate compensation) is when someone has smaller and more frequent snacks of carbohydrates. Both methods get the job done by filling up the muscle glycogen stores with carbohydrates. However, gorging can sometimes cause stomach problems because the body is not used to it. Because of this reason, I would suggest using the moderate compensation or nibbling plan. Below are the steps;

  • Gradually reduce training over 6 days
  • Start with a mixed diet of 50-60% carbohydrates
  • Increase the diet to contain 70-80% of its calories from carbohydrates

A Common Mistake

Many people try to consume more calories in order to carbo-load. However, this will only result in extra weight that has to be carried around on race day. The goal of carbo-loading is not to bulk up on food, but to fill the muscle glycogen stores. Any extra calories will just be converted into fat. Even most of the skinniest elite marathoners have enough fat reserves to be able to run multiple marathons.

 Try to stick to the same amount of calories that you typically eat on race day. Just change the percentage of carbohydrates in your diet.

Do you carbo-load for your races? How do you do it?


3 thoughts on “The Wall and Carbo-loading

  1. Pingback: Fueling During Exercise | Joy Runner

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s