Planning your carbohydrate intake for a marathon: the complete checklist

Race nutrition is sometimes called the "4th discipline" of a marathon, following endurance, speed, and mental preparation. A poorly prepared carbohydrate plan can ruin months of training in a single day. Here is a complete, phase-by-phase checklist.

The week before the race

• Gradually increase your carbohydrate intake starting 3 days before the race (carb loading), without radically changing your usual diet.
• Test your final dosage of Endurance Fuel during your last long run, not on race day.
• Check that your Soft Flask is clean and that you know how many servings it contains for your target pace.

The day before and the morning of the race

• Carbohydrate-rich meal the night before, with no new foods.
• Breakfast 2 to 3 hours before the start, always using foods already tested during training.
• Prepare your Endurance Fuel portions in advance: one flavor per flask if you are using multiple flasks, to vary the taste over time (Tropical Passion, Watermelon-Lime, Peach-Mango).

During the race

• Start fueling within the first 30 to 40 minutes, even before you feel hungry.
• Aim for 60 to 90 g of carbohydrates per hour for efforts lasting over 2.5 hours, thanks to the 2:1 glucose-to-fructose ratio already calibrated in the formula.
• Alternate flavors if you are using multiple servings to avoid flavor fatigue, an underestimated factor in the spontaneous drop in intake toward the end of a race.
• Don't forget electrolytes, especially if the temperature is high: the 500 mg per serving covers a portion of the sodium lost through sweat.

After the race

• Replenish your glycogen stores with a carbohydrate intake within 30 to 60 minutes of finishing.
• Rehydrate gradually, taking into account the sodium losses accumulated during the effort.
• Note what worked (or didn't) during the race: your strategy is refined race after race.

The checklist at a glance

• 7 to 3 days before: gradually increase carbohydrates
• Last long run: test the final dosage
• The night before: carb-rich meal, nothing new
• Morning: tested breakfast, prepared portions
• 0-40 min into the race: start fueling
• Every hour: 60-90 g of carbohydrates + electrolytes
• Post-race: carbohydrates + rehydration within the hour

A good nutrition strategy isn't decided on marathon day: it's built during training, one long run at a time.