Exercise Substrate Utilisation and Endurance Performance Following Short-term Manipulation of Dietary Fat Intake

Dietary fat intake positively influences the ability to burn fat during exercise in women but not men, whereas carbohydrate intake negatively influences fat oxidation in both sexes. The independent nature of dietary fat intake as a predictor of the ability to burn fat in women suggests that in conditions of adequate carbohydrate intake providing additional fat may increase fat oxidation in women whereas it does not in men. It is of interest to explore if indeed women are responsive (i.e., increase in fat oxidation) to short-term increases in dietary fat intake induced by overfeeding (adequate carbohydrate) or if as appears to be the case in men reduced carbohydrate intake as typically employed in high-fat, low carbohydrate dietary studies is also a prerequisite for enhancing fat oxidation in women, and whether this translates into a difference in exercise endurance performance.