What is carb loading and how to do it successfully: The complete guide

pasta dish

It is no longer a secret that nutrition plays a tremendous role in your health and overall performance. Carb loading is a short-term strategy that can help improve your performance.

This strategy is often used by bodybuilding competitors, runners and many other athletes.

Some people wonder if carb cycling is a myth and others doubt in its effectiveness.

However, it is a short-term strategy proven to support performance. In this article, we will focus on steps and guidelines for performing carb loading for bodybuilding, athletics, running and competitions as well as feeding strategies that you can implement to make it more effective. In addition, we will also cover some cautions and common mistakes.

What is carb loading?

Carb loading is a strategy that involves eating more carbohydrates than usual and reducing exercise to increase the levels of glycogen.

Glycogen is a name given to carbohydrates that are stored within the body. They are stored in two places: liver and the muscles. If you’re interested in finding out how carbohydrates are digested and absorbed, then take a look at this post.

Carb loading was developed by scientists in the 1960s, they found that making changes to diet and exercise prior to an event could result in extremely high levels of muscle glycogen.

The potential benefit of increased muscle glycogen is a 20% increase in overall endurance capacity allowing a given pace and intensity to be sustained for longer. In addition, there is an improved hydration status because every gram of glycogen can hold three grams of water.

How does carb loading improve performance?

Carb loading is a very effective strategy for increasing glycogen concentration in the muscle and prolonging its depletion. This can improve performance by delaying the decline in plasma glucose, allowing a higher rate of carbs oxidation later in exercise.

A person performing endurance activities lasting longer than 90 mins would certainly benefit. This includes activities like marathons, triathlons, and cross-country skiing.

Those participating in explosive anaerobic activities and sprint sports lasting up to 30 mins show no benefit from carb loading.

How to do carb loading?

If you’ve ever wondered when to start carb loading before an event, whether you are a runner or a bodybuilder there are a few strategies you can implement.

However, the purpose of each strategy is to simply increase the glycogen stores by increasing carbohydrate intake as well as reducing exercise.

The traditional 6-day carb loading

This carb loading strategy lasts for 6 days, and must be performed 6 days prior to an event.

For the first three days of this strategy, only 15% of your total daily calories should come from carbohydrates. For step-by-step guide on calculating your calories, check out this post here.  During these days, you should continue exercising as normal to decrease the levels of glycogen first.

Then, during days four to six, 70% of your total daily calories should come from carbohydrates and this is when you minimise exercise too. As a result, your glycogen stores will greatly increase.

Modern 6-day carb loading strategy

The current research has shown that depletion of carbohydrates for the first three days may not be necessary.

As a result, the modified version of the 6-day strategy follows different rules.

For the first three days, this program involves eating a moderate-carb diet with 50% of your total daily calories coming from carbohydrates. Then, your carbohydrate intake needs to increase to 70% of your total daily calories.

In regards to exercise, over the period of 6 days you should just gradually decrease it with no more than 20 minutes of exercise in day 5 and 6.

The traditional 3-day carb loading strategy

This strategy is shorter but may be a little harder for some.

A day before you start carb loading, it is important to perform the most intense and exhaustive exercise your body can possibly handle. Then, for the three days of carb loading, your intake of carbohydrate should be approximately 70% of your total daily calories and whilst performing no exercise.

Modern 3-day carb loading strategy

As I mentioned earlier, current research shows that depleting the body from glycogen stores may not be necessary. As a result, the modern 3-day strategy is identical to the traditional one but you just don’t perform the exhaustive exercise at the beginning.

You just don’t exercise at all for the three days.

 1-day carb loading strategy

The last but not least is the 1-day strategy. This is the simplest one and potentially not as effective as others but suitable for the last-minute boost before an event.

All you need to do is avoid any exercise for 1 day and eat a high-carbohydrate diet. Participants in studies using this strategy consumed 4.5g of carbohydrates per 1lb of their bodyweight [1].

How to carb load for bodybuilding

When it comes to carb loading for bodybuilding the key strategy focuses on depleting your carbohydrate intake during the first couple of days, followed by high-volume weight training. You’re essentially looking to deplete your body’s store of carbohydrates over a period of around 5 days. In addition to dropping your carb intake during this period you should also mildly increase your protein to help account for the extra volume.

After 5 days of reduced carbs your muscles will be ready for carbohydrates so on day 6 you can load up on carbs eating a high carb diet which is approximately 70% of your total daily calories. You should also aim to reduce your water intake during carb loading as your muscles will take excess water from your skin helping you to look more sculpted prior to a competition.   

Common mistakes

1. Doing it when you don’t need to

Don’t perform carb loading for the sake of just performing it as it is only effective in certain circumstances. Those participating in explosive anaerobic activities and sprint sports lasting up to 30 mins show no benefit from carb loading. Anaerobic exercise refers to high intensity interval training that normally lasts 20-30 minutes. Carb loading for bodybuilding is an effective way of adding volume to muscles prior to competition.

This strategy is only effective for exercise and events requiring more than 90 minutes of exercise.

2. Too many calories

When you perform carb loading, it is important to adjust other macronutrients like protein and fats to ensure you are eating the right amount of all nutrients.

High fat intake can result in excess calories making you gain weight and potentially feeling demotivated.

In addition, high fat intake can reduce the Glycaemic value of carbohydrate which may intervene with the carb loading strategy.

3. Wrong carbohydrate intake

Eating the wrong amount of carbohydrate can totally ruin the purpose of carb loading.

Therefore, you need to ensure the intake of carbohydrate is right.

To do this, make sure to firstly calculate your daily calories then use the percentages shown above to calculate your intake.

For instance, if the total calories were 1,500 per day and you want to eat 70% of carbohydrates then your equation will look like this :

1,500 x 0.70 = 1,050 calories for carbohydrates

1,050 / 4 = 263 grams of carbohydrates (because there are 4 calories in each gram of carbs)

4. Exercising more than you should

Exercise depletes the stores of glycogen so if you perform more exercise than you should then it completely defeats the purpose of carb loading.

Make sure to follow the guidelines per each strategy, whichever one you choose and minimise exercise on specific days.

Good and bad food options

By now you know that it is important to eat high carbs and avoid foods that are high in fibre and fats. The table below shows some good and bad options to take into consideration.

Foods To eatFoods to avoid
Low Fibre cereals like corn flakesCrackers
Fruit juice and smoothiesMuffins
White ricePastries
Applesauce and marinadesBrownies
White potatoes Donuts
White bread and pretzelsfried chips or French fries
sugary fruit like bananas and watermelonespizza


Carb loading is a short-term strategy that helps improve performance for bodybuilders and athletes. It includes increasing carbohydrate intake and reducing exercise for a few days prior to an event. This increases the glycogen stores and in turn helps you perform harder for longer.

Have you enjoyed today’s post? I’d love to hear your opinion below!

If you’ve enjoyed todays post then make sure to subscribe to our newsletter below to be updated when new posts are uploaded as well as get nutrition and exercise tips and exclusive discounts.

Subscribe below to download 6 FREE fat loss recipes and 20 nutrition and exercise tips.


* indicates required
No payment method connected. Contact seller.

Related posts

Leave a Reply

Your email address will not be published. Required fields are marked *