Carbohydrate Loading

In the days leading up to a big event such as a marathon or triathlon, many athletes enter into a state of carbohydrate loading or “carbo-loading.” To the average person, carbo-loading evokes an image of a skinny runner eating as much pasta as humanly possible the night before the big race. However, carbo-loading should be approached much more scientifically, and there are quite a few misconceptions when it comes to this important component of distance training and racing.

Why do athletes carbo-load?
When an athlete consumes carbohydrates, the body converts this macronutrient into glycogen, which is stored in the muscles and liver. When the body requires energy during an endurance event, the stored glycogen is efficiently converted into glucose for quick consumption. Carbo-loading before a race or important workout ensures optimal storage of glycogen and helps avoid “hitting the wall” at the end of an event.

When should I start carbo-loading?
Carbo-loading should begin 2 – 3 days before the race. Your body is limited in how much glycogen can be stored (up to 2,500 calories worth), so loading too far in advance could result in excess of unnecessary carbohydrates, which could lead to weight gain.

How many carbohydrates should I consume?
During carbohydrate loading periods, you should consume 8 – 10 grams of carbs per kg of body weight.

Can I eat any carbohydrates?
A common myth is that carbo-loading entitles an athlete to consume anything and everything placed in front of him or her, most notably desserts such as cookies and candies. In reality, your meals should contain wholesome sources of carbohydrates, such as brown rice, quinoa, sweet potatoes, and cereal grains. The night before the event, simple carbs may be preferred by runners in order to avoid an overabundance of fiber.

Can I eat an unlimited amount of carbs?
No. Since your body can only store a limited amount of fuel, eating beyond the recommendation of 8 – 10 g of carbs/kg body weight is not advisable. Additionally, you should limit each meal to approximately 800 calories in order to allow for optimum carbohydrate storage. During carbohydrate loading, more frequent, yet smaller meals are recommended. Drinks such as orange juice or Gatorade can also be implemented in between meals.

Are there any foods I should avoid while carbo-loading?
Fatty foods can inhibit the conversion of glycogen into glucose so they should be avoided. During carbo-loading, diets should consist of 70 – 85% carbohydrates.

How will carbo-loading make me feel?
Some athletes may feel bloated during carbo-loading because for every gram that is consumed of carbohydrates, the body will retain 3 – 4 grams of water. However, this water retention is beneficial during long races and serves as an extra source of hydration.

Should I continue consuming carbohydrates on the day of the race?
Yes. Race day breakfast is extremely important and should be comprised almost exclusively of carbohydrates. For any event lasting longer than 75 minutes, athletes should continue to take in 20 – 60 grams of carbs per hour to avoid “bonking.”

We would like to know your comments about carbohydrate loading. Please leave a comment below or visit us on Facebook.