Carbohydrate loading, or "carbo-loading," is a strategy endurance athletes use to maximize muscle glycogen stores before competition. When done correctly, it can improve performance by 2-3%—which in a marathon can mean several minutes.
The Traditional Approach
Old-school carb loading involved a depletion phase (training hard while eating low-carb for 3-4 days) followed by a loading phase. This caused fatigue and wasn't necessary. Modern carb loading is simpler.
Modern Carb Loading Protocol
For events lasting 90+ minutes: consume 8-12g of carbs per kg of body weight daily for 36-48 hours before the event. For a 150-pound person (68kg), that's 540-820g of carbs daily—about 2200-3300 calories from carbs alone.
Focus on low-fiber, easily digestible sources: white bread, rice, pasta, potatoes, bananas, sports drinks. Too much fiber can cause GI distress during the event.
Who Benefits Most
Carb loading helps events lasting longer than 90 minutes at intensity above 65% VO2max. For shorter events or lower intensity efforts, regular nutrition suffices.
