How do you eat during a marathon?

Are you about to start a marathon and wondering how to feed yourself during a marathon? Whether it’s your first marathon or you have done it before, it’s very important to prepare your nutrition strategy for a marathon. You do not want to make any mistakes that could ruin your entire marathon preparation!

One of the sticking points with a marathon is that this multi-hour effort will severely deplete your carbohydrate stores. A diminishing supply affects performance, and that’s when you reach your limits.

Hitting the wall

Scientists are divided on the origin of the “hitting the wall” pattern in a marathon. For some, it’s initially central fatigue: The nervous system takes advantage of too much effort to stay active – this is called homeostasis. For others, it is external fatigue: The muscles are damaged by psychological and chemical reactions.

These two types of fatigue are caused by an important effort, but also by a lack of fuel for the body. In order to contract, muscles need ATP (adenosine triphosphate). This ATP is produced by fat and carbohydrates. The faster you run, the more carbohydrates you consume, and this is often the case at the beginning of a marathon. As soon as this supply of carbohydrates is used up, you start to fall back on your fat reserves, and with lower yield: your speed decreases.

So you need to replenish your carbohydrate reserves

Carbohydrates are stored as glucose in the blood, as hepatic glycogen in the liver, and as muscle glycogen in the muscles. These stores remain limited: between 2000 and 2200 kcal for liver and muscles combined.

You must be careful to optimize these stores in the days leading up to the race by replenishing them with carbohydrates. Eat carbohydrates and easily digestible food in the days before the race.

Nutrition on the morning of the marathon

The rule on the morning before the race is not to eat too much. You need to eat enough to gain energy, but not too much. It is recommended to eat 3 hours before the race for optimal digestion. Foods you can think of include: Pancakes, energy cakes, honey, stewed fruit. Or why not have a salty meal with a small bowl of rice with ham or tuna.

Most importantly, do not forget to stay hydrated: tea, herbal tea, water. Carry a water bottle with you so that you can have a sip of water every now and then until the start.

Drinking during the marathon

The most important factor is hydration. This is important in any weather, but it is even more important when it is more than 68°F outside. If you are dehydrated, it is too late.

Typically, in a marathon, aid stations are scheduled every 5 kilometers or every 2 miles (New York City Marathon). You need to take 2-3 sips of water at the first aid station, even at the 5th mile, even for those running less than 3 hours. If you run the marathon in more than 4 hours, you will have to take even 5-6 sips of water, because the time gap between two aid stations is bigger.

Water is your best ally when it comes to marathons. An isotonic or high-energy drink is a good idea, but not really practical since you have to carry a water bottle. It also makes it heavier! If you take 75 cl of isotonic water, you already weigh 750 g more! Only the elite runners who finish in less than 2 hours 20 minutes can usually carry private water bottles, which is probably not the case for you.

Isotonic drinks are sometimes provided at aid stations, depending on the sponsor of the marathon. If you plan to take any of these during the race, you will need to test them in training beforehand to be sure you can tolerate them in terms of taste and digestion. So find out in advance about the different positions and the list of refreshment points on the course prepared by the organization.

Eating during the marathon

As far as nutrition during a marathon is concerned, it is necessary to take into account the duration of the race.

For the first part of the race, it is recommended to eat foods with a low glycemic index, such as stewed fruit, mashed potatoes, energy bars (which can be chewed effortlessly)… A nutrient with a high glycemic index will give you an immediate boost, but will also cause your blood sugar levels to drop. This phenomenon is called hypoglycemia and is the biggest enemy of endurance runners.

How many energy gels do I need to take for a marathon? Be careful not to take an energy gel in the first hour! That would create a blood sugar spike too early in the race, followed by an urgent feeling of hunger. The digestive tract of most runners is not capable of handling eight or ten gels.

Food for a marathon in less than 3 hours

If you are running a marathon in less than 3 hours, the interval between two aid stations 5 kilometers apart is between 15 and 20 minutes. We recommend a first carbohydrate supply at kilometers 10 (or 15) and 20, for example with mashed potatoes or fruit compote. From 25 kilometers you can take energy gels, for example at kilometers 25, 30 and 35.

Remember to drink enough water with each food intake, even if it is only 2-3 sips.

Get supplies during a marathon between 3 and 4 hours

The time between two aid stations is estimated at 20 to 30 minutes. You can opt for mashed potatoes, stewed fruit or energy bars from the 10th kilometer, then energy gels from the 15th and 20th kilometers. Then you can take energy gels for the 25th, 30th and 35th kilometers. Remember to drink water with every food intake, even if it’s only 4-5 sips.

Get food supplies for a marathon in more than 4 hours

The time between two aid stations is estimated to be 30 to 45 minutes. This means that if you miss an aid station, you will not have anything to eat until 1 hour or 1 hour and 30 minutes later. Therefore, you must not miss any water provision and should ideally start eating at kilometer 5, for example with half a fruit compote or an energy bar. Nutrients with a longer propagation of carbohydrates are important at the beginning of the race. It can also be parts of mashed bananas if they are available in your marathon food supplies.

Later you will resort to energy bars, because for the 25th kilometer you will have to run between 2 and 3 hours, which is a lot, because staying only with gels as food is not the best. We advise you to take the energy gels or sugar cubes only from the 30th kilometer, and on the 30th, 35th and possibly on the 40th kilometer.

Remember to drink 5-6 sips of water with each food intake, and a little more if it is very hot. You can also have a small bottle of 25cl that you fill up when you eat to drink regularly between two intakes.

The express food at a marathon … or not

If you want to break your personal record in a marathon, do not linger at an aid station. Take the trail ahead and slow down a few meters before to take your cup and gulp your food and drink. Always be considerate of other runners, and sometimes it is better to run a little slower than to miss your aid station.

Try not to stop completely so you do not get out of rhythm and lose your progress. At some aid stations you can walk a few meters to relax your legs and muscles. The same applies if you start to suffer from cramps, you can also walk on this occasion.

Everyone has their own nutrition strategy for a marathon

We give you some advice on the great principles of nutrition in a marathon. Everyone must refine their nutrition strategy according to their experience. A marathon is first and foremost a matter of self-knowledge and performance. After several marathons you will know what is best for you, even if it takes many races to find out what is best for you.

Be sure to get used to long distance training to try out your nutrition strategy. You can also replace a product that does not suit you with another brand. For example, the composition of gels can vary greatly from manufacturer to manufacturer.

So, I wish you a good preparation and a great marathon! 😉 With the right nutrition strategy and proper training, you can persevere and maybe even break your personal record! At the last Paris Marathon, runners between 2h29 and 5h15 used the RunMotion Coach app to prepare for the big day and benefit from specific advice for marathons, including the nutrition part.

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Mailis Durif-VarambonMailis grew up in the mountains, where she went hiking and biking every weekend. She loves outdoor activities where she can relax at the end of the day. At RunMotion Coach, she is responsible for community management.