Eating Before and During Your (Half) Marathon

Marathons and half-marathons are often considered the ultimate goal for runners. The finish line is like the final exam after a season of training.

Nutrition in the days leading up to the marathon is critical for maximizing results, even if the diet itself can seem a little unconventional.

Two to three days before the event

Competitive runners say that in the case of a half-marathon the party starts two days before the event, and three days for a full marathon. This is when you’ll want to pump your body with glycogen, meaning you’ll be carbo-loading to boost your body’s energy stores.

Concretely, this means replacing the fat and protein in your diet with carbs. Eat pancakes with maple syrup and fruit, pasta with tomato sauce, flavoured yogurt, bagels packed with jam, fresh and dried fruits, cereal and oatmeal—in short, a ton of sugar! Runners joke that they compete solely for the pleasure of eating before the race.

If carbs are king during marathon week, water is queen. It’s extremely important to show up 100% hydrated on race day, so it’s important to increase your water intake dramatically. The quantity of water is different for everyone, but be sure to drink at least three litres of water per day, and avoid drinking alcohol two days before the event. Alcoholic beverages have a dehydrating effect on the body which could impact your performance.

Race Day

On the morning of the race, you’ll need to opt for carbs and limit your consumption of fat and protein, as they take longer to digest. Choose refined carbs (without fibre), such as white bagels with jam in order to avoid digestive issues and combine them with a drink that is also rich in sugar, such as juice, chocolate milk, or a smoothie. The more time you allow to elapse between breakfast and the race, the heartier your breakfast should be.

The important thing is to prepare a meal you’ve tested prior to race day and under the same conditions. This doesn’t mean you have to run a marathon the week before, but try eating the same breakfast three hours before training if you plan on eating it three hours before the marathon. You want to avoid trying something new at all costs. 

During the race

Hydration, hydration, hydration! If you have one thing to consider during the race, hydration is it!

Pick a sports drink that contains lots of sugar and minerals (sodium, potassium), such as Gatorade, or try making a homemade version with water and orange juice in equal quantities and adding a pinch of salt. Avoid drinking (solely) water, as you won’t replenish any of the minerals you shed while sweating.

The carbs that you accumulate during the days before the race are what will give you the energy necessary to run—but only for about an hour. It’s important to continue to consume sugar throughout your race so that you have enough energy to cross the finish line. Energy gels are a smart option because they’re easy to carry and quick to consume, on top of being mostly made up of sugar. Try them out before the marathon, and be sure to take them with lots of water to avoid gastric distress. Bits of orange and banana along with dry fruit are great options as well.

With your body’s stores of sugar and water, your sugar-rich snacks and immaculate hydration prior to the race, you truly are stacking the odds in your favour.

So ready, set... Eat!

In collaboration with Ève Crépeau, Dt.P.