GLUCOSE + FRUCTOSE IS BETTER THAN GLUCOSE-ONLY AS AN EXERCISE SUPPLEMENT
Triplett, D., Doyle, A., Rupp, J. C., & Brenadot, D. (2008). A glucose-fructose beverage improves 100-km cycling performance compared to a glucose-only carbohydrate beverage. ACSM 55th Annual Meeting Indianapolis. Presentation number 851.
This study determined if a beverage containing glucose and fructose improved cycling performance more than a glucose-only beverage. Male competitive cyclists (N = 9) completed two simulated 100-km cycling time trials on a Lode cycle ergometer separated by 5-7 days. The 100-km trials contained four 1-km sprints at 10, 32, 52, and 72 km and four 4-km sprints at 20, 40, 60, and 80 km. Ss were encouraged to complete the entire distance and each individual sprint as quickly as possible. During the trials, subjects received 36 grams of carbohydrate containing isocaloric amounts of glucose or glucose and fructose in 250 mL of water every 15 minutes.
All Ss completed the 100-km time trial faster when they received the glucose-fructose beverage compared to glucose alone. Individual sprint performances were not significantly different between beverages. There was no significant difference at any time for blood glucose or blood lactate. Total carbohydrate oxidation increased significantly during exercise but was similar for the beverage conditions.
Implication. Consumption of a carbohydrate beverage containing glucose and fructose results in improved 100-km cycling performance compared to that produced with an isocaloric glucose-only beverage.
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