2. There is an optimal macronutrient ratio.
Should your diet be 60 percent carbohydrate, 20 percent fat, and 20 percent protein, as many sports nutrition experts recommend? Or should it be 40 percent carbohydrate, 30 percent fat, and 30 percent protein, as other experts contend. Or is the optimal macronutrient ratio for endurance performance something else? In fact, science has shown that there is no such thing as a one-size-fits-all optimal macronutrient ratio.
Individual runners need different amounts of the three macronutrients based on how much they train. Consequently, while a 60/20/20 breakdown might be perfect for one runner, it might not be for another runner. Carbohydrate requirements vary the most with training volume. Think in terms of absolute amounts of carbohydrate instead of percentages. The average runner requires about 2.5 grams of carbs per pound of body weight daily, but elite runners who train 20 hours a week or more may require twice that amount.