Trail race fueling: what should you eat and drink on the move?

Many runners are all too familiar with gastrointestinal distress and digestive problems during exercise. They are among the leading causes of withdrawal, especially over long distances. These issues are caused not only by the vibrations generated while running, which can speed up transit and trigger acid reflux, but also by reduced blood flow to the digestive system, which makes it work much less efficiently. Race-day fueling therefore needs careful planning to reduce the risk of discomfort and digestive trouble.

Self-sufficient, semi-self-sufficient or regular aid stations: every race has its own setup

Aid station frequency varies from race to race. Some events are fully self-sufficient, others semi-self-sufficient, while some offer regular aid stations. To avoid surprises on race day, you need to plan your strategy around the spacing of the aid stations provided by the organizers. The amount of food and fluid you carry will depend on the location and contents of the official aid stations, as well as your own strategy. You may use the food provided by the organizers alongside your personal supplies, or rely entirely on what you carry. It’s up to you to find the winning combination.

Whatever the setup, remember that the body cannot tolerate every food when it is working hard. Test your options in training and work out what agrees with you and what does not, bearing in mind that every athlete is different. Something you digest without a problem may not suit another runner at all. Unfortunately, bad experiences are often what teach us which products work best for us. One golden rule applies: NEVER try a new food or drink in competition. Always validate your race fueling in training.

The key to successful fueling for running and trail races

• Your energy intake must be sufficient to maintain muscle and liver glycogen stores.

• Food and fluid intake during exercise should limit mineral losses and prevent dehydration. Drink 500 to 800 ml per hour of running, with each intake limited to 100 to 150 ml every 15 minutes.

• Exercise makes the body more acidic. It is therefore important to cut back on acidifying foods that contribute to muscle fatigue, digestive problems and cramps.

• Watch your sugar intake! Sugar causes most digestive problems during exercise. It is a fuel source, but refined sugar is highly acidifying. Fast-acting, high-glycemic sugars also increase the risk of reactive hypoglycemia and cause blood glucose levels to swing. Combining solid food and fluids, it is advisable not to exceed 80 g of sugar per hour.

• Favor unsaturated fats, in other words foods made with almonds, sesame, pecans and similar ingredients.

• Liquid nutrition is easier to digest and easier to take in, which can be difficult during exercise. A good-quality sports drink containing a little salt can help replenish depleted glycogen stores and may be all you need for efforts lasting less than two hours.

• Avoid energy gels: they contain almost nothing but sugar, and in excessive quantities at that, with one gel providing around 20 g of carbohydrates on average. This can contribute to digestive problems and reactive hypoglycemia.

• Take in small amounts at a time. It is better to eat and drink regularly than to take in a large amount once in a while!

Race fueling: what should you eat and drink during a trail race?

To help you choose from the aid-station tables or put together the “doggy bag” you will carry with you, here are two lists: foods to avoid and foods to favor.

TO AVOID

Because they are acidifying, difficult to digest or irritating to the digestive system, or because they encourage reactive hypoglycemia

• Highly processed and industrial foods

• Orange juice and orange segments (they often cause heartburn)

• Lemon cordial

• Almonds (an ecological disaster in California, the main producing region, and with a less favorable lipid profile than hazelnuts or walnuts)

• Crisps

• Gruyère

• Salted or unsalted peanuts

• Energy drinks and alcoholic beverages

• Soda, although Coca-Cola can still be useful from halfway through the race onward

• Cereal bars and bread

• Sweet biscuits

• Savory crackers, although Tuc crackers can be an acceptable compromise for getting some salt without too many harmful additives

• Coffee

• Cocoa and chocolate

• Candied fruit, jam and candy

• Energy gels

TO FAVOR

Because they are alkalizing, easy to digest, or provide good fats or quality carbohydrates

• Grape juice (rich in potassium and antioxidants, and ideal combined with Saint-Yorre water)

• Mint, peach or red-berry cordial

• Wholegrain toast

• Hazelnuts and walnuts

• Cured ham or viande des Grisons

• Fresh, dried or stewed fruit: apricots, apples, pears, peaches, bananas, dates, figs...

• Fruit juice: apple, grape, banana...

• Vegetables in hot or cold soup

• Still or de-gassed mineral water

• Chestnuts

• Potatoes

• Rice

• Avocado

• Olives

• Sea salt

• Marzipan

• Fruit paste

• Sweet or savory sports cake

• Sports gingerbread

Fueling for an ultra

Long-distance events come with a particular challenge: they require substantial fueling while being especially likely to cause digestive problems. One of the keys to success in an ultra-endurance event is therefore managing to eat properly and sufficiently throughout the race, knowing that your needs and cravings will change as the kilometers go by. Often, only experience and a finely tuned understanding of your own body make it possible to plan fueling precisely during a long event.

Choosing foods you enjoy is essential because, during a long effort, fueling should provide a moment of comfort. Food needs to stimulate your appetite, especially since physical exertion can have an anorexigenic effect, in other words, it can completely suppress the desire to eat.

When the effort lasts a long time, as it does in an ultra-trail race, protein intake becomes particularly important. An athlete’s body uses an average of 30 g of protein per hour during an endurance event. The aim of taking in protein is not to replace all of that loss, but to prevent too steep a drop. Athletes often use BCAAs because a fall in BCAA levels leads to an increase in another amino acid, tryptophan, which is not only soporific but also suppresses appetite. Protein should come from solid or liquid foods.