Marathons and carbohydrates: What to do and what not to do

What are the best practices for marathon success?

Because of the distance involved, a marathon must be approached with a different strategy than shorter races. Your choice of “fuel” before and during the race will strongly impact your goals. Indeed, a lack of it will inevitably lead to a certain difficulty around the 19th mile: the wall! Some know it, some fear it.

Avoiding the famous marathon wall 

First of all, we recommend a training program adapted to your level, which lets your body learn to save energy and be more efficient. If your preparations aren’t optimized, no nourishment strategy will be effective. Your strategy must be tested during three or four long outings in order to simulate your race!
Reloading on carbs for two or three days before your goal will stimulate your reserves and help you finish your marathon with more intensity.

To do this, you must:

  • • Figure out your strategy, hour by hour
    • Figure out the best times for your training and long outings

What should you eat before a marathon?

Carbs are the favored source of energy for high-intensity workouts. When you reload on carbs, you’re filling up your energy reserves.
 (Le repas d’avant course) (CI39)

A study by the International Journal of Sports Medicine noted that during a marathon, only 12% of runners consumed enough carbs before the race, and that these runners ran 13.4% faster than a comparable group of runners who ate fewer carbs.

The latest nutritional recommendations suggest around four grams of carbohydrates for each pound of body weight, which is much higher than most runners are used to eating. To give you an idea: to reach this amount, you would need to consume one to two liters of sports drinks throughout the day.

During the two days leading up to the marathon, increase your carb intake to ensure that your reserves are packed full of energy.

Your refueling strategy

When refueling, the ideal is to reach the right amount of carbs per hour of race. If it’s too low, you won’t reach your full potential. If it’s too much, you risk having gastrointestinal problems.

La littérature scientifique préconise :

  • Consume 45-60 grams of carbohydrates per hour (equivalent to 1-2 pills per hour)
  • Space out your carb intake at every 30 minutes to reduce gastrointestinal troubles
  • Drink four to eight ounces of water each time you consume carbs depending on how much you’re sweating

Thanks to your pills and your final pre-race meal, it’s not necessary to add electrolytes (sports drinks) during your race.

In fact, pairing pills with sports drinks can dehydrate your body.

Nothing changes the day of

No matter the distance, do not experiment with new strategies or new products on the day of the race.

You run the risk of:

  • Nausea
  • Gastrointestinal problems
  • Being appalled by the texture or flavor

Now it’s up to you! Enjoy your run! You Run, We Care For more running and health advice, use the Running Care app.

Written by:

Guillaume Boitel – Doctor in Physiology, Bio-mechanics, and Sports Sciences

You Run, We Care

For more running and health advice, use the Running Care app !