Muscle Glycogen and Endurance Performance
Muscle glycogen—stored carbohydrate—fuels high-intensity endurance exercise. Depleting glycogen stores results in fatigue and performance decline, particularly in efforts exceeding 90 minutes. Carbohydrate loading increases muscle glycogen to maximum capacity.
The Original Carb-Loading Protocol
Early research recommended "depletion loading": five days of fat and protein with minimal carbohydrate to deplete stores, then three days of carbohydrate loading. Modern approaches skip the depletion phase.
Contemporary Carb-Loading Strategy
Three to four days before competition, gradually increase carbohydrate intake while decreasing volume and intensity of training. This combination maximizes glycogen storage without causing discomfort or weight gain.
Carbohydrate Quantity
Calculate requirements as 7-12 grams of carbohydrate per kilogram of body weight daily during loading days. A 70 kg runner requires 490-840 grams daily during loading—approximately 55-75% of total calories.
Food Choices During Loading
Focus on easily digestible carbohydrates: white rice, pasta, bread, potatoes, and bananas. These maximize glycogen storage without causing digestive discomfort. Avoid excessive fiber during loading days.
Meal Timing Before Competition
Eat a substantial meal of easily digestible carbohydrates 3-4 hours before competition. Include small amounts of protein and minimal fat to avoid digestive issues. Examples: toast with honey, pasta with tomato sauce, or rice with white chicken.
Race Day Fueling
For events exceeding 90 minutes, consume 60 grams carbohydrate per hour through sports drinks, gels, or bars. This maintains blood glucose as glycogen depletes, sustaining performance.
Individual Variability
Carb-loading effectiveness varies substantially. Some athletes gain 3-5% performance improvements; others notice minimal benefit. Practice race-day nutrition during training to understand personal response.
← Back to Home