In the following article, you'll find many useful tips if you're preparing for a marathon or other long-distance race. Our dietitian, Agnieszka Gruszka, has prepared the most important information, a foundation for every marathon runner.
Practical tips for marathon runners
Preparing for long-distance races is a process in which nutrition plays as important a role as the running training itself. Whether the goal is a half-marathon, marathon, or ultramarathon, a runner's body must cope with regular, often prolonged, exertion. Proper nutrition helps maintain energy, improve recovery, and reduce the risk of overuse injuries and health problems during the season.
The role of nutrition in long-distance running training
For a long-distance runner, eating is not only a way to satisfy hunger, but a tool supporting adaptation to large training volumes. With several sessions per week, long runs, and often additional supplementary training, the body needs a constant supply of energy and nutrients.
Nutritional neglect can lead to:
- increasing fatigue and decreased motivation,
- problems with regeneration after long training sessions,
- more frequent infections and lower immunity,
- difficulty maintaining pace in the final phases of exercise.
Energy balance – the basis of long-distance endurance
In long-distance races like the marathon, maintaining an appropriate energy balance is crucial. Too little calorie intake, even if it doesn't produce any noticeable symptoms initially, can lead to a decline in performance and recovery problems over time.
In practice, it is worth remembering that:
- days with long runs or training lasting over 90 minutes require a significantly higher energy supply,
- not every training day should look the same nutritionally - eat more on hard days, less on recovery days (but still be in a calorie balance, not in a deficit - the body needs energy to regenerate),
- Unplanned weight loss during preparation is often a sign of undereating, not improved fitness.
The goal of nutrition is not weight control, but maintaining the ability to follow a training plan in the long term.
Macronutrients – how do they support marathon runners?
Macronutrients are an important element in composing a marathon runner's daily and pre-workout diet. Make sure you're choosing them correctly, and if not, make some changes to your diet.
Carbohydrates – a runner's basic fuel
Carbohydrates are the main source of energy during long-term exercise, such as a marathon. Adequate amounts of them help replenish muscle glycogen stores and maintain the quality of training, especially when performed at race pace.
Examples of carbohydrate sources in a runner's diet:
- white and brown rice,
- wheat and whole grain pasta,
- groats (millet, bulgur, couscous, buckwheat),
- potatoes and sweet potatoes,
- oat flakes,
- wheat and rye bread,
- fruits (bananas, apples, pears, berries),
- honey, jam, rice waffles - especially useful around training.
In practice:
- Base your daily diet on complex carbohydrates, and consume easily digestible sources around training. An interesting solution would be, for example:. Czarniecki pasta with added fiber on non-training days or around training noodles.
- • Test products and carbohydrate amounts on long runs – this is the best time to check your tolerance to gels, bars or drinks. To do this, test, for example,. Marathon Runner Set from B-PAC – this will help you know how you react to these products.
- After a long workout, the priority is to quickly replenish glycogen stores, which means a carbohydrate-protein meal no later than one hour after exercise.
Protein – regeneration and adaptation to training
Protein plays a key role in muscle recovery and the body's adaptation to repeated stress. For long-distance runners, a regular daily protein intake is crucial, rather than a single, high dose.
Examples of protein sources:
- eggs,
- poultry (chicken, turkey),
- lean beef,
- fish (salmon, cod, tuna, mackerel),
- dairy products (natural yogurt, kefir, skyr, cottage cheese),
- legumes (lentils, chickpeas, beans),
- tofu and tempeh,
- quinoa.
In practice:
- After very long workouts, pay special attention to your post-workout meal.
- Natural sources of protein are usually sufficient – supplementation is an addition, not a requirement.
Fats – health and long-lasting energy
Fats are an important part of a long-distance runner's diet, especially during moderate-intensity exercise. They support hormonal and immune system function and vitamin absorption.
Examples of fat sources:
- olive oil,
- canola oil,
- avocado,
- nuts (walnuts, almonds, cashews),
- seeds (pumpkin, sunflower, linseed, chia),
- oily sea fish (salmon, sardines, herring, mackerel).
In practice:
- Take care of the quality of fats by avoiding excess fats before training.
- In very long units, fat tolerance may be important - test it gradually.
- Fats support hormonal health and immunity, which is crucial when consumed in large volumes.
Hydration – an element often underestimated
In long-distance running, even mild dehydration can significantly reduce performance and running comfort during a marathon. Proper hydration affects muscle function, thermoregulation, and concentration.
In practice, it is worth:
- drink regularly throughout the day, not only during, but also immediately before and after training,
- during long runs, learn to hydrate in small portions, not only water, but also an isotonic drink – check out this one from B-PAC by AronPharma,
- Remember to drink fluids even on colder days when the feeling of thirst is weaker.
The most common mistakes of marathon runners
The same problems often arise among amateur long-distance runners:
- replenishing energy too late after training (after more than an hour or even later),
- lack of a consistent nutritional strategy for long training sessions or no strategy at all,
- experimenting with new products just before launch,
- underestimation of fluid requirements.
Remember that a conscious, consistent approach to nutrition not only improves the quality of your training but also helps you avoid crises and derive greater satisfaction from long-distance running. After all, you want to finish the Gdańsk Marathon in the best possible shape, right?
In the next dietary article you will find information on composing the daily diet of a marathon runner, including more about the glycemic index, the importance of micronutrients, nutrition supporting regeneration and example meals.
Agnieszka Gruszka, Sports dietitian and psychodietician
For years, she has been combining scientific knowledge with sports practice. In the past, she trained as a regatta sailor, and triathlon was her sporting adventure. Currently, she is active in mountain biking and running. In her work, she provides nutritional support to athletes of various disciplines, including young competitors—including her son Grzesiek, who trains mountain biking.
