How do I prepare for a half-marathon?


Running a half-marathon requires not only good training but also good nutrition. To achieve good performance during this challenge, runners must make their bodies function at the highest level on D-Day. Different strategies also come into play: adaptations to training, rest and diet.

A nutritional strategy during a half-marathon must not only satisfy the nutritional needs of the runner but also not be restricting or create any digestive pain.

Preparing for your half-marathon

This phase allows you to prepare your body for the half-marathon. You need to keep an eye on any changes in weight, which may require an adjustment in energy expenditure linked to the increase in training and daily calorie intake. A balanced diet facilitates energy management, thus helping to maintain a stable weight.

5 – 6 weeks before the half-marathon

  • Make sure that you have a strict balanced diet and a good healthy lifestyle.
  • Do not miss any meals and eat at regular times,
  • Meats, fish, eggs: 1 to 2 times a day to provide proteins,
  • Starchy food: at each meal to ensure energy intake,
  • Dairy products: 2 to 3 times a day to provide protein and calcium,
  • Fruits and vegetables: 5 a day to provide water, vitamins, and fibre,
  • Fats: vegetable fats are preferable in reduced quantities,
  • Sugar: limit consumption,
  • Obviously, drink as much water as you can.

D-7: last week

  • Keep a balanced diet,
  • Increase your carbohydrate intake to grow your energy stores,
  • Increase your water consumption to ensure some water reserves,
  • Limit fatty meats.

D-3 and D-2: last days

  • Increase your carbohydrate intake again, using maltodextrin: 1 to 2 bottles a day,
  • Limit your intake of raw fruits and vegetables, because they are rich in fibre and can speed up bowel movements.

D-1: The day before the half-marathon

  • Keep a carbohydrate-rich diet
  • Consume 2 shakers of maltodextrin
  • Keep drinking fluids throughout the day.
  • Limit your intake of raw vegetables in case your digestion is sensitive

Start day

The last meal must be effective, high in carbohydrates, and easy to digest (limit fibre and fat). Ideally, it should be eaten 3 hours before the start to ensure it is properly digested.

Its main aim is to maximise energy reserves.

Eat an Ultra energy cake within 3 hours of the start to ensure your energy supply for later, without causing digestive issues.

During the race


Avoid dehydration

Avoid hypoglycaemia and the complete exhaustion of energy reserves

Compensate for vitamin and mineral losses

Avoid digestion problems.


The majority of half-marathon runners start the race without a flask or water bottle even though it is recommended to drink regularly and right from the start of the race! In any event, you mustn't wait to feel thirsty before drinking. The refreshment stands are therefore very important as they offer cold water. Don't miss them!

Several solutions for avoiding hypoglycaemia:

  • Consuming ISO drinks (but this means you need to carry a water bottle during the race).
  • Consuming Energy gel: easy to eat and practical to carry. They need to be consumed with water. Ideally they should be taken before each refreshment break and for the final ¼ of an hour of the race.
  • Consuming an 'Ultra bar: Chewing during the race can be restrictive, so take along products that are easy to chew.



Compensate for water losses,

Restore energy reserves.

Restore vitamin and mineral losses

Repair damaged muscle fibre.


As soon as you cross the finish line, you need to consume water to compensate for fluid losses, carbohydrates to restore your energy supply, sodium to compensate for losses in sweat, and proteins to help with muscle repair. You can get all of this with the After drink, which includes all these elements in perfect proportions.  


To avoid digestive problems, during training sessions you should test the products you will be using for the race. Indeed, the type of food ingested during a marathon is a very personal choice.

Half-marathon pack

- Maltodextrin

- Ultra energy cake

- Energy gel

- After drink

Marie Fauchille
Dietician | Nutritionist
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