Nutrition 20 Things Runners Should Know About Carbs

20 Things Runners Should Know About Carbs


By: Andy De Santis, RD MPH

Carbohydrates are the single most important fuel source for a highly active person. They are found in many foods but mostly in whole grains, fruits and vegetables. If you are a runner, your ability to properly fuel yourself may be a pivotal factor that separates you from your average and peak performance. There are several important characteristics about carbohydrates that would help just about anyone to know, and I will try to several of them today. Some of them you may have encountered before, but others may surprise you but each of them has unique value in terms of your overall health and performance.

Did You Know?

  1. The glycemic index (GI) is a measure of how much a carbohydrate-rich food raises your blood sugar. White bread has a GI of 100 while steel cut oatmeal has a GI below 55.
  2. Foods with a higher GI are generally digested and absorbed more rapidly than foods with a low GI , which are digested and absorbed more slowly
  3. Although low GI foods are generally considered to be better choices, it may be beneficial to consume high GI carbohydrates in the hours prior to racing or training as they are more readily absorbed.
  4. If you are a very active person, the amount of carbohydrates your body requires will vary depending on the intensity of your training schedule.
  5. The average person should aim to consume about 45-65% of their calories from carbohydrates
  6. An athlete or very active person should aim to consume between 3 to 10 grams of carbohydrates per kilogram of bodyweight a day.
  7. You should aim to consume more carbohydrate on days where you run more than usual or you run more than once.
  8. You should consume extra carbohydrates in the 24-48 hours before a big race.
  9. In the 1-4 hours before training or a race, you should consume a carbohydrate rich meal.
  10. Dietary fibre is a form of indigestible carbohydrate that has very important effects on our health.
  11. There are two types of dietary fibre: insoluble and soluble. Each is type of fibre has a different beneficial effect on our body.
  12. Soluble fibre (as in oats, beans) generally slows down digestion while Insoluble fibre (vegetables ,most whole grains) helps food travel more easily through the digestive system. These effects offer unique short and long-term benefits to our digestive and overall health.
  13. You should aim to consume a fibre-rich diet, but it may help you to avoid fibre-rich foods in the hours before training runs or big races as they take longer to digest.
  14. Low carbohydrate, high fat diets (ie: most fad diets) are not recommended for runners.
  15. Whole grains, fruits and vegetables are the most important sources of dietary fibre and other nutrient for the general population and especially athletes.
  16. Certain carbohydrates, such as those found in beans/lentils/chickpeas, may cause gas in some people and may need to be avoided before a big race or event.
  17. Sugars are a type of carbohydrate that are essentially “smaller” than other types of carbohydrates and are found naturally ( such as in fruits) or added to many foods ( such as pop).
  18. Currently, Canadians consume about the same amount of sugar from fruit as they do from sugar-added beverages.
  19. Although the consumption of sugar-added beverages is generally not recommended, very active people may benefit from consuming sports drinks (ie: gatorade, powerade) in specific situations.
  20. In events that involve intense exercise of duration > 60 minutes, consuming sports drink may contribute to improved performance.

Andy is a Toronto-based private practice dietitian and nutrition writer/blogger. You can learn more about Andy’s background, services and explore his blog at