In a 2016 position, the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine acknowledge that maintaining high carbohydrate availability enhances performance during prolonged sustained or intermittent high-intensity exercise while depleted carbohydrate stores is associated with fatigue. Ongoing research continues to support the consumption of multiple forms of carbohydrate to enhance more rapid absorption and availability of carbohydrates. Sucrose, containing both fructose and glucose, is a blend of carbohydrates that is readily available. Other considerations include the availability of more complex carbohydrates based on digestion. Nonetheless, research in some performance athletes suggests that fructose may play a role in maintaining and restoring body carbohydrate stores such as liver and skeletal muscle glycogen stores that are depleted during prolonged exercise.
Research Study Summaries
Postexercise Repletion of Muscle Energy Stores with Fructose or Glucose in Mixed Meals
A recent study published in the American Journal of Clinical Nutrition asserts that consumption of fructose “lowers whole-body glycogen synthesis and impairs subsequent exercise performance, presumably because of lower hepatic glycogen stores.” The study sought to compare “isocaloric mixed meals containing fat and protein with either pure fructose or pure glucose” on intramyocellular lipids (IMCL), […]
Liver Glycogen Metabolism During and After Prolonged Endurance-Type Exercise
A 2016 literature review published in the American Journal of Physiology Endocrinology and Metabolism describes the involvement of liver glycogen in prolonged exercise and discusses the most effective nutritional strategies for liver glycogen repletion. Gonzalez et al. report that the total volume of liver glycogen in trained endurance athletes is no different than that of […]
Fructose May Help Maintain Liver Glycogen during Prolonged Endurance-type Exercise
Previously published research has shown that carbohydrate feeding during prolonged (>2 hour) moderate-to-high intensity, endurance-type exercise enhances endurance performance and capacity. The improvement in exercise performance has previously been attributed to high rates of carbohydrate oxidation which prevent hypoglycemia and may spare muscle glycogen. However, it is well known that glycogen stores in the liver […]
The role of carbohydrates, including fructose, on athletic performance reaffirmed by several health organizations
While most adults need to watch their caloric intake, athletes need to be conscious of the amount, type and timing of calories to help ensure optimal performance. The recent position by several professional organizations, including the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine, continues to support the […]
Fructose May Help Recovery from Heat- and Exercise-Induced Dehydration
Kamijo et al examined whether carbohydrates in beverages could promote enhanced fluid retention after heat and exercise induced dehydration, and if this improvement was a result of an enhanced renal sodium reabsorption rate due to insulin secretion.