Sansum Clinic Nutrition for Athletes: Carb Loading – How to Correctly Harness Your Energy

Sansum Clinic Registered Dietitian, Emily Luxford, breaks down carb loading for athletes. Almost as soon as we are taught to ride bikes, run the mile or compete in athletic events, we are encouraged by our athletic mentors to “carb load.”

What does this mean?

Let’s break it down…



Often considered as grains and pastas,
carbohydrates also include food groups
such as starchy vegetables, fruit & milk

For your good health

Having the proper energy stores is an important part of maximizing your performance potential

Having the proper energy stores is an important part of maximizing an athlete’s performance potential


What is a carb? A carb or carbohydrate is a macronutrient. This type of nutrient is consumed in large amounts in the typical diet. The most important function of carbohydrates for the athlete is as an energy source. Foods considered part of this macronutrient family include grains, cereals, starchy vegetables, fruit and milk. To “load” is to provide your body with excess nutrients.

When you consume carbohydrates, they’re broken down into glucose (single sugar molecule) and some of that glucose is stored in your muscles and tissues as glycogen. Consider this your “rainy day” fund. The purpose of carbohydrate loading is to maximize the storage of glycogen in the muscles allowing plenty of energy for that “rainy day”. Endurance athletes exercising for greater than 90 minutes benefit from the increased glycogen stores achieved through carbohydrate loading. Individuals participating in short intensity or moderate intensity exercise do not need to load carbohydrates. Instead, they should maintain a moderate intake of carbohydrate, 45-65% of their daily caloric intake.

Loading carbohydrates 24 hours before an event will not provide the body with the necessary stores needed to compensate for prolonged activity. Dietary modification to supplement your nutrient stores must begin at least one week prior to any endurance sporting event. As you modify your carbohydrate intake, it is also important to modify your exercise training program. By decreasing training time the athlete allows the body to store glucose as glycogen and build an adequate energy supply for game day. Use the schedule below as a guide and modify it to meet your needs.

Training Day Training Time grams carb/kilogram body weight*
1 90 min 5
2 40 min 5
3 40 min 5
4 20 min 10
5 20 min 10
6 Rest 10
7 Event Day Event Day Diet

* To find your weight in kilograms (kg), divide your weight in pounds by 2.2.


More Sansum Nutritional Information for Athletes

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