Carb Loading Before A Run

Carb Loading

Photo By: Beau Maes

When I ran my first marathon a few years ago, I was researching like crazy the proper nutrition needed to help me get through the race. If there was a special food source that helped newbies like me make it to the finish line, I wanted to know about it!

Ever since my track days in high school I always heard about carbo loading before a big race to help you keep your pace. Of course, when I was in high school there was a lot of different information out there on what exactly was the proper way to load up on carbs. I mean, lets be honest here, does a kid running a 200 meter dash need to carbo load? Nope, but they did!

Anyways, now that I am back in my running spirit, I decided to take a look at carbo loading now and how people are using it to help achieve their marathon goals.

A Brief History

After scouring the web, I found this nice article on the history of carbo loading, and how the whole idea is based on military research from 1967, which has progressively changed as more studies were conducted.

To sum up their findings – a carbohydrate depletion phase, followed by a carbohydrate loading phase gives your muscles the ability to store more glycogen (energy for your muscles) compared to your muscles before the carbohydrate depletion phase initially began.

So basically, if your body’s muscles have more energy (glycogen) to use, that should equal both a faster time at longer distances (perfect for a marathon!)

But why does this affect your glycogen levels? Wouldn’t it be just like filling up a glass of water after drinking it completely? The glass isn’t getting bigger?

Well, from my understanding, our bodies are pretty interesting. Go without food for awhile, once you have food, your body holds on to as much of the calories/fat/carbs/proteins as possible because it thinks you are in “starvation” mode.

This is the same thing for your muscle’s energy levels.

Depletion Phase is Depleting

According to an article by Running Times, the whole depletion phase of the the carbo loading practice has faded away, as many runners who have started training intensely for a marathon are already inadvertently depleting their bodies of carbohydrates anyways.

So nowadays, people just bulk up the amount of carbs they eat a few days before the big event to help boost up the glycogen in their muscles. This is when we see the picture of the skinny marathon man eating what looks like four boxes of pasta on one ginormous plate.

So Does It Work?

Obviously there has been evidence of this kind of diet before a race gives runners more energy. Will it work for you? That is up for you to decide.

There are a few important considerations to think about though before jumping into a bag of bagels and bread:

  1. Try to avoid eating anything “new” – especially foods you weren’t eating while training. Something may sound delicious, but it could make your stomach a little crazy – you don’t want that before race day.
  2. You cannot digest all of the carb necessary to fill up your “glycogen tank” in one meal – it is going to take a few days. Don’t just think a large pasta dinner the night before a marathon is the best way to fill up.
  3. Try to avoid fiber and protein which can fill you up a lot faster than carbs. Which means, stay away from some fruits which can be full of fiber. Bananas however, are both fun to say and are low in fiber (high in carbs).
  4. You are eating more CARBS, not more food (calories). Too many people I know start eating double the amount of food they normally eat because they feel they need to eat a bunch of carbs and that is the way to get it done. It is about just shifting the food you eat, not necessarily eating more food. has a great article on pre-race food nutrition that can help you make the right choices in your diet.

More on carbo-loading can be found in Runner’s World Runner’s Diet: The Ultimate Eating Plan That Will Make Every Runner (and Walker) Leaner, Faster, and Fitter.

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