How the sugar level of high-carb diets over 5 days affects energy use and running ability in men

No significant differences were found in fat and carbohydrate oxidation rates or endurance capacity between high glycaemic index and low glycaemic index diets after 5 days of high carbohydrate consumption.

• A total of nine healthy males participated in three treadmill runs to exhaustion.
• Running was performed after a habitual diet, a high carbohydrate/high glycaemic index diet, and a high carbohydrate/low glycaemic index diet.
• Both high carbohydrate diets resulted in lower plasma glycerol concentrations and higher carbohydrate oxidation rates compared to the control trial.
• The glycaemic index of the diet did not influence fat oxidation rates during running in the fasted state.

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