Performance Athletes

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), […]

Read More

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 […]

Read More

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 […]

Read More

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 […]

Read More