That’s why it’s important to accurately estimate your own Basal Metabolic Rate (BMR) — the number of calories your body burns at rest. This value is essential for planning your nutrition, especially if you're physically active.

The BMR can be calculated using a simple formula:

• Women: BMR = weight (kg) × 22

• Men: BMR = weight (kg) × 24

In addition to your Basal Metabolic Rate (BMR), your total daily calorie needs depend heavily on your activity level. The more active you are, the higher your energy requirements. Here's a simple formula to help you estimate:

• Inactive: BMR × 1.2

• Low activity (physical effort 1–2 days per week): BMR × 1.3

• Moderate activity (physical effort 2–3 times per week): BMR × 1.4

• High activity (intense physical effort 3–5 times per week): BMR × 1.5

• Very high activity (daily intense physical effort): BMR × 1.7

For optimal performance, you should eat between two and four hours before your activity. This gives your body enough time to replenish glycogen stores.
Light, balanced meals are ideal, such as brown rice with chicken, beans, and salad; porridge with milk, berries, and seeds; or sweet potatoes with bell peppers, spinach, and salmon.

About 60–90 minutes before exercise, it’s advisable to top up your energy reserves with isotonic drinks, homemade green smoothies, chocolate oat milkshakes, dried fruits, or similar snacks.

For most activities lasting less than an hour, drinking water is usually sufficient—provided you’ve adequately replenished your glycogen stores beforehand.

However, if you’re active for more than an hour, a study from the University of Texas shows that consuming 20–60 grams of carbohydrates per hour during exercise can help delay fatigue and improve performance.

The best carbohydrate sources for this include dates, potato pancakes, energy bars, sports drinks, or fruit snacks with a high glycemic index (GI), which are quickly converted into blood sugar. For especially intense activities like trail running, it’s also recommended to focus on low-fiber foods with a high GI.

The best time to refuel is as soon as possible after physical exertion. Glycogen replenishment happens fastest within the first two hours—typically at 130–150% of the normal rate. During the following four hours, the replenishment rate remains high, but at a slower pace.

Note on recovery foods:
Numerous studies have shown that combining protein and carbohydrates is more effective for restoring muscle glycogen and promoting muscle tissue growth than carbohydrates alone.
Homemade oat bars, whole-grain sandwiches with lean protein and leafy greens, peanut butter and banana sandwiches, or yogurt drinks can work wonders.

While many people advocate for keto, paleo, or low-carb diets during intense physical activities, numerous studies since the 1960s have shown that a carbohydrate-rich diet is crucial for sustained endurance performance.

Carbohydrates are needed as fuel for almost every activity—and you need to “refill the tank.” The faster you can replenish it, the better. This is partly due to the amount of glycogen stored in your body (which can hold up to 2,000 calories in the form of glycogen—1,600 in muscle cells and 400 in the liver) and your glycemic index (GI), an important factor in the speed at which carbohydrates are converted into glycogen.

Muscle glycogen serves as the “fuel” for physical activities. Low muscle glycogen levels lead to quicker fatigue, while high muscle glycogen levels allow you to perform longer and at higher intensity.

Liver glycogen helps maintain blood sugar levels. When blood sugar drops, liver glycogen is converted into glucose and released into the bloodstream.

Guidelines for calculating carbohydrate needs:

• Short duration/activity: 5–7 g per kg of body weight per day
• Moderate duration: 7–10 g per kg of body weight per day
• Long duration (athletes): 10–12 g per kg of body weight per day

Protein is a component of every cell and tissue in your body, including muscle tissue, skin, hair, tendons, and internal organs. It contributes to the growth of new tissue and the repair of existing tissue, regulates metabolism, serves as an important energy source, and supports the production of hormones and enzymes (including insulin and adrenaline).

During intense endurance activities, your body’s protein requirements increase to compensate for the higher breakdown of protein already present in your body. When muscle glycogen stores are depleted—usually 60 to 90 minutes after starting intense physical activity—your body sources additional amino acids, which are converted into glucose by the liver. This glucose is then released into the bloodstream to support your muscles, contributing up to 15% of their energy production. Conversely, when muscle glycogen stores are full, protein contributes less than 5% to energy needs. Additionally, protein is needed for the healing and recovery of muscle tissue after strenuous endurance activities.

Guidelines for calculating protein needs:

• Inactive: 0.75 g per kg of body weight per day
• Moderate activity: 1.0–1.2 g per kg of body weight per day
• High activity: 1.2–1.4 g per kg of body weight per day
• Very high activity: 1.4–1.7 g per kg of body weight per day

Fat is an important nutrient because it contains essential fatty acids your body needs to build hormones and cell membranes, among other things. Fat also provides you with fat-soluble vitamins A, D, E, and K. It is a crucial component of brain tissue, bone marrow, nerve sheaths, and it cushions your organs like a protective pad against injury. However, not all fats are the same! Different fatty acids make the difference. Besides saturated fats, there are also monounsaturated and polyunsaturated fatty acids.

1. Saturated Fatty Acids
   Saturated fats are found in animal products such as butter, cream, cheese, bacon, sausages, and meat. They are also present in many processed sweet foods like cakes, cookies, and pastries. We should minimize saturated fats in our diet because they increase cholesterol levels, especially LDL cholesterol (LDL stands for Low Density Lipoprotein) and are considered a major cause of heart disease.

2. Unsaturated Fatty Acids
   Most of the fat we consume should come from high-quality unsaturated fats, which are found in fatty fish (mackerel, fresh tuna, river trout), seeds (flaxseeds, pumpkin seeds), nuts (walnuts), avocado, kale, or spinach.

Monounsaturated fats can lower total cholesterol levels, especially LDL cholesterol, while keeping the “good” HDL cholesterol (HDL stands for High Density Lipoprotein) stable.

You can find monounsaturated fats in olive oil, canola oil, hazelnut oil, olives, nuts, seeds, and avocados.

Polyunsaturated fats are found in fatty fish, fish oils, sunflower oil, and sesame oil. Although polyunsaturated fats can also lower LDL cholesterol, studies show they may slightly reduce the “better” HDL cholesterol as well.

In general, no more than 15% of an athlete’s daily calorie intake should come from fat. However, many studies show that people in Europe and the USA currently consume between 30% and 35% of their calories from fat sources on average.

When traveling to distant destinations, it makes sense to buy only a minimum of essential ingredients at home. This way, you save food miles, reduce CO2 emissions and shipping costs, and can often purchase fresher ingredients or those with fewer preservatives locally.

There are several ways to preserve food for your trip. Cooling or freezing with a powerful cooler box is only suitable for short tours above freezing temperatures, but it has the advantage that the food retains its fresh taste and intense aroma. On the downside, cooler boxes are heavy and expensive, and they are not suitable for every type of trip.

Food can also be preserved by drying. Besides dry staples like grains and legumes, many other dry goods such as herbs, spices, and sugar are easy to transport. An exception is travel in humid areas like jungles, where dried foods must be packed airtight to prevent spoilage. The advantage of dried foods is their low weight and compact size. The downside is that flavor and some vitamins can be partially lost.

Another option is freeze-dried meals. They have a very long shelf life, are lightweight relative to their calorie content, experience minimal vitamin loss, and are easy to rehydrate and prepare. Freeze-dried fruit powders offer many benefits on long trips due to their low weight compared to nutritional value, minimal vitamin loss, and easy use in breakfast meals, shakes, recovery drinks, and even homemade energy bars.

The major drawback: the high cost.

To avoid picking up germs or pathogens through food or drink while on the move, proper hygiene must be observed. Heating food kills germs. Fresh foods should be thoroughly washed with hot water. Dishes and cutlery should also be cleaned with soap and hot water. Drinking water must either be guaranteed to be of drinking water quality, filtered through a 0.2-micron filter, properly sterilized with a chlorine solution, or boiled vigorously for 5 minutes (at altitudes below 1,000 meters — longer at higher elevations). Proper storage and prevention of cross-contamination must also be observed.

More about food hygiene certifications:

• HACCP Level 1 Training
• Certified Principles of Food Safety HACCP Level 2 Online Course