Trail running is a sport that is very hard on the human body and will tend to "break" a large quantity of muscle fibres. The right nutrition will help to prepare for this while also slowing down and then repairing these breaks. This discipline also eats up a large amount of energy, which makes the food you eat before, during and after your trail run doubly important.



The food you eat during the week prior to your trail run will play a significant role in defining your physiological condition on the day of the race. Here are the objectives:

-        Top up your glycogen reserves (glycogen is the means by which glucose is stored in the muscles and liver).

-        Maintain perfect hydration.

-        Avoid or reduce problems with digestion.

-        Avoid any vitamin and mineral deficiencies.

During an intense and/or prolonged physical activity, such as the trail run, your glycogen reserves will determine how long you can maintain a high level of effort.

Glycogen reserves depend on the following:

-        Your diet: the carbs in your diet are what will be used to synthesise glycogen.

-        Your training level: a trail runner with more training will have a greater capacity to store glucose in the form of glycogen.

-        Your hydration: You need 2.7 mL of water to store 1 g of glycogen.

From D-7 to D-5, reduce your carb intake slightly so that your muscles start to "demand" more carbs. Then, between D-4 and D-2, gradually increase your carb intake again until D-1 when your diet should be back to normal in terms of quantities. Take care to avoid food that you find more difficult to tolerate (if in doubt, drink less milk and eat less dietary fibre). Always drink plenty of fluids (2 L per day, preferably with maltodextrin).



Preferably choose food that you can digest easily and more quickly because the stomach, and especially the intestines, are less well irrigated during physical activity.

If this is not already the case, have a reserve of water (hydration pack) with you and drink every ¼ of an hour if you were properly hydrated when you started: take a mouthful each time you drink, i.e. the equivalent of about 3 sips. An energy drink is preferable to water and reduce the dose a little when the conditions are very hot. For short trail runs (less than 1 hour 30 minutes), a drink that is high in minerals and vitamins will be enough. A good example of this are the Aptonia Electrolyte Tablets which also have the benefit of being easy to carry if you need to make more drink during the physical activity. In addition to this, it is very important to choose an isotonic carb drink such as Aptonia's ISO for activities ranging from 1 to 3 hours or the ISO+ when the event exceeds 3 hours. Eat half an energy bar or a gel every 25 to 35 minutes to avoid overloading your digestive system. From the choice of bars, it will be beneficial to select a few protein-rich bars in order to reduce the damage to the muscle fibres.

Make the most of the training sessions to test your tolerance to the bars, gels and energy drinks, as well as to get you accustomed to eating while running. Eat during some relatively easy sections to avoid any risk.



-        To rehydrate

-        To restore your glycogen reserves

-        To repair micro-lesions in the muscles

-        To rebuild your immune defences

-        To restore the pH balance

-        To combat the production of free radicals

If it is possible to eat a meal within one hour of finishing the trail run, make sure you drink water with a high level of bicarbonate and sodium (Saint Yorre, Vichy Celestin, etc.) as well as eating a meal composed of the following:

Fruit and vegetables (for their vitamin and mineral content)

Carbs (to restore your glycogen reserves)

Red meat or lean fish (to repair the muscles)

A dairy product

A small amount of fat (e.g. rapeseed oil)

You may continue drinking water with a high level of bicarbonates and sodium until you go to bed that night.

If you cannot eat a meal within one hour of the race, you would benefit from drinking a carb or protein rich recovery drink within 30 minutes of finishing the physical activity. As for the evening meal, stick to the same diet suggested for the meal to eaten within one hour of the trail run.



As a sports enthusiast since forever and a triathlete for five years, I'm at my best when doing long distances (marathons, Ironman® etc.). I'm quite proud to have finished as the first-place Frenchman during the Ironman 70.3 World Championship in September 2017 in the US. Besides working for Decathlon, I'm also a nutritionist. I work with numerous sports users to help them with their meal planning and nutrition. Physical activity and good nutrition? Two (very good) solutions to stay fit!