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Carb Loading 101

You've probably heard of carb loading before but maybe you figured it wasn't for you or it just meant that you ate that pasta dinner the night before the race to get some extra carbs. In this post I'll walk you through the why, when, and how of carb loading so you know exactly how to implement it to see those performance enhancements you're looking for.


WHY Should I Carb Load?

If you have big goals of a PR or getting on the podium at a race you need to make sure that training + nutrition is dialed in. This is usually not something that happens by chance. A key strategy that is used in longer distance races is carb loading. Studies show that endurance performance improvements are seen with high carbohydrate availability. On average, with fully stocked glycogen stores, you can expect to see a 2-3% improvement in performance. That can be the difference between snagging that PR and not. Or it could mean finishing the race strong instead of hitting the wall at mile 18 and having to drop out.

WHEN Should I Carb Load?

You don't need to carb load before that 5k because your glycogen (your body's stored carbohydrates) will not become depleted during that time. Typically we think of carb loading for races that will last >90 minutes so half marathons and farther. Carb loading should start about 3 days out from your event--like I said--eating a big bowl of pasta the night before isn't enough. It takes some planning ahead to make this happen

HOW Do I Carb Load?

Let's get down to the good stuff--how do I actually do this?!

Step 1: Calculate how many grams of carbs you need to consume each day by using this formula

(A)Your body weight in lbs/2.2 =(B)your body weight in kg

(B) Your body weight in kg x 8 = (C) the number of grams of carbohydrates you should consume each day starting 3 days out from your race

Step 2: PLAN it out. You are not going to just happen to eat 400+ grams of carbs each day. It may sound exciting at first but if you haven't mapped it out it's not going to be easy. This is where working with a Dietitian or grabbing my FREE Carb Loading Guide can come in handy.

Here are a few things to keep in mind when planning this out:

  • Don't think of your 3 day carb load as a time when you're necessarily eating more food--rather think of it as eating more carbs and less of everything else. Carbs should be the star of your meal and protein and veggies are more like the sides. Your plate should look like the hard day performance plate.

  • Stick with carb sources that are lower in fiber to avoid GI issues.

  • Eat things that you normally eat--just have more! The few days leading up to a race are not the time to try out new foods.

  • Use fluids like juice and sports drink to help meet your daily carb goal

Step 3: Grab your groceries based on the plan you just mapped out. Remember that you're going to be purchasing more carbs than usual. While a pack of bagels used to get you through the week it may only last 1-2 days during carb loading. The last thing you want to do this week is have to run to the store every day. If you'll be traveling for your race this becomes even more important. Either grab the items you need before you get to your destination or hit up a grocery store while you're there. Even if you're staying in a hotel, at the very least you're going to need some snacks. I may be known to carry around a box of Ritz crackers the day before a race when I'm traveling and picking up my packet and getting settled into the hotel.

Step 4: Follow your plan. Eat and drink the specific amounts of carbs you determined for each meal and snack. This is not a time when we are eating intuitively and that's ok. This is what sports nutrition is about. Using nutrition not just for optimal health, feeling good, or avoiding disease but rather to enhance performance and that means that there are certain times when we have to be intentional with nutrition.

Be sure to grab my FREE Carb Loading Guide so that you can go into your next race with a fully stocked tank! If you need help with your daily nutrition or creating a race day fueling plan, you can email me or book a FREE Intro Call and we can chat about the best options for you. I have several different ways we can work together that fit any budget!

Kayla Fitzgerald is a Registered Dietitian & Certified Intuitive Eating Counselor and founder of Endurance Nutrition located in Charleston, South Carolina. She works with clients 1:1, through small group coaching, and self guided programs. Her goal is to help you fuel your body for whatever the day has in store whether it's a 100 mile race or getting through the work day.

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