Carbohydrate fueling recommendations cannot be generalized because energy expenditure varies widely based on exercise intensity, fitness, efficiency, and substrate utilization. As exercise intensity increases, the body relies progressively more on carbohydrates than fat, with even moderate exercise capable of burning over 100 grams of carbohydrate per hour. By understanding energy expenditure and respiratory exchange ratio (RER), athletes can estimate how much carbohydrate and fat they are using during exercise and better appreciate why glycogen stores are rapidly depleted.
Read more of Aaron's own words from the Carbs Fuel Website: https://carbsfuel.com/blogs/news/energy-expenditure-and-fueling-during-endurance-exercise-part-1