Berning, J. R., Leenders, M. M., Ratliff, K., Clem, K. L., & Troup, J. P. (1993). The effects of a high carbohydrate pre-exercise meal on the consumption of confectioneries of different glycemic indices. Medicine and Science in Sports and Exercise, 25(5), Supplement abstract 125.

Different forms of carbohydrates have different rates of digestion and provide varying rates of release of glucose into the blood.

After consuming a high CHO meal (84% CHO, 11% protein, 5% fat) two and one half hours before a 90 min bicycle ride, a high glycemic (HG) or low glycemic (LG) candy bar was ingested. A no-feed control condition was also employed. [Examples of high glycemic foods are honey, bagels, most candies, raisins, most sport drinks. Low glycemic foods are applies, cherries, dates, figs, milk, and yogurt.]

Blood glucose and insulin were found to be higher in the low glycemic candy bar group than either of the other two conditions. Blood free fatty acids (FFA) were highest in the unfed trial while the LG trial was higher than the HG trial during the ride.

Implication. A low glycemic confectionery will continue to provide sustained energy during prolonged exercise by maintaining plasma glucose and FFA at higher levels during an extended endurance performance.

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