Carbohydrates Do Not Improve Endurance Performance
December 14, 2008 | Leave a Comment
Carbs are the main fuels for muscular exercise at intensity more than 65% of maximum effort. Our bodies actually use carbs for fuel during intense exercise because they give useful energy a lot quicker than fats or proteins. Carbohydrate sources during exercise include the following:
-Muscle and liver glycogen (stored carbohydrate)
-Carbohydrates absorbed following meals
-Conversion of chemicals (Alanine, Pyruvate and Lactate) into blood sugar by the liver
Several athletes eat high carbohydrate meals faithfully prior to a competition or before training. However, we don’t know that much about the effects of carbohydrate complexity on performance.
At the Chinese University of Hong Kong, researchers discovered that the type and amounts of carbs contained in the pre-exercise meals had absolutely no effect on endurance performance.
They also compared the effects of pre-exercise meals having high and low combinations of glycemic index (the rate that a food boosts blood sugar) and glycemic load (the total carbohydrate type of the food) ate 2 hours before exercise on 10K running performance.
The participants ran for 1 hour at 70% effort before consuming the low glycemic index meals.
Lastly, the study only investigated the effects of one pre-exercise meal on performance. Eating the same meals for a few days in a row might have produced a variety of results.
Source: International Journal of Sport Nutrition and Exercise Metabolism, 18: 281-300, 2008
