Why carbohydrate recommendations during exercise aren’t based on body weight

Typically, nutrition requirements are based on individualized factors such as age, weight, gender and level of physical activity. For instance, protein requirements can range from 0.8 grams/kg body weight per day for an inactive healthy adult to 2.0 grams/kg of body weight per day for an active individual looking to lose body fat. This can evidently create a variety of nutrition recommendations. However, when it comes to carbohydrate intake during exercise, recommendations are given in absolute terms without regard to factors such as weight. Ever wonder why that is? Read on to find out.

Carbohydrate needs during endurance events can range from 30-60 grams/hour for exercise lasting 1-2.5 hours to 60-90 grams/hour for exercise lasting more than 2.5 hours. There is an upper limit set for carbohydrate recommendations because there is a limit to how much the body can absorb at once. Going above this maximum limit will not increase carbohydrate absorption but can actually cause water to be drawn into the intestine.

This ability to absorb carbohydrates is independent of body mass. This means that a small athlete and a larger athlete will absorb the same amount of carbohydrates if all other factors are the same. This is why carbohydrate recommendations during exercise are given in absolute terms rather than per kg of body mass like other nutrition recommendations.

While body mass doesn’t influence ability to absorb carbohydrates, the gut is adaptable. Individuals who regularly consume carbohydrates or have a high carbohydrate diet have an increased ability to absorb carbohydrates.  This is of significance for endurance athletes who want to perform at their best, as the ability to absorb and use carbohydrates as a fuel source increases endurance capacity. In other words, by consuming carbohydrates during prolonged exercise you can perform at a given intensity for a longer period. What athlete wouldn’t want this?

Got an upcoming race? Ignore the low carb hype. If your goal is to perform at your best, you’ll want to be able to absorb as much carbohydrates as possible. The gut is trainable just like your muscles. Practice your in-race fuelling plan weekly and include ample carbohydrates in your day to day diet.

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2019-06-10T17:47:54+00:00 June 11th, 2019|

About the Author:

Learn to fuel your health and performance with Megan Kuikman, Registered Dietitian. Megan provides professional nutrition advice that you can trust. To work with Megan, call: 519-802-9445 or e-mail megankuikmanRD@gmail.com.