Nutrition Guide for Marathon Runners

Training for a marathon demands more than simply increasing your running distance. The body requires enough energy to complete the demands of the session, recover from the workouts and be ready to perform on the race day.

Marathon day running nutrition plan should support the entire training cycle and not just the last few days prior to the event. The right marathon runner diet is a combination of carbohydrates, healthy fats, proteins, micronutrients and fluids adjusted according to the training period. [1]

Why Nutrition Matters for Marathon Training

Marathon training increases the expenditure of energy and puts the muscles under repetitive stress. If the food intake does not meet the training demands, runners may experience lack of energy and slower recovery. Studies have highlighted the importance of adequate energy and macro nutrient intake on health and performance. A good running nutrition therefore starts with consistency.

This matters the most during long distance running, where repetitive sessions increase the nutritional demands. Instead of depending on a single perfect meal, build a routine which provides adequate nutrition through the day. The needs can vary as per the body composition, training intensity, distance of race and tolerance of the individual.

A customized marathon runner diet may help to meet the intake with these demands. A dietary assessment can help to identify the nutritional gaps and support the individualised nutrition strategies.1

Key Nutrients Every Marathon Runner Needs

Carbohydrates

The main fuel for marathon training is carbohydrates. The glycogen in the muscles and the blood glucose provide energy for the working muscles. Low glycogen availability can contribute to fatigue and tiredness.[2]

Endurance runners usually require a greater proportion of carbohydrates than the general population, although the exact amount should be as per the training demands and individual characteristics.1

Select foods such as rice, oats, potatoes, whole grains, fruits which are carbohydrate sources. Before any long training sessions, carbohydrate intake becomes really important. For exercise that lasts between 1 to 4 hours, the required carbohydrate intake can be 1 – 4g/kg body weight, at least 1- 4 hours before exercise. [3]

Protein

Proteins are required by the body for muscle protein synthesis and recovery. Distribute your protein across all the meals rather than having larger portions at one sitting. Sources for protein include –

·         Dairy products (curd, yogurt, paneer, milk)

·         Non vegetarian (egg, fish, chicken, lean meat)

·         Soy and soy products

·         Pulses, legumes (chickpea, kidney beans, moth bean)

Adequate protein is particularly necessary for maintenance of muscles and supporting recovery in endurance runners.1

Healthy Fats

Fats are needed by the body to support normal physiological functioning. Sources for healthy fats include nuts, oilseeds, nut butters, avocado and plant oils. However consuming high fatty meals just before your exercise may increase the gastric discomfort.

Therefore, keeping pre activity meals comparatively lower in fat can be beneficial. A high fat meal pattern is generally not recommended as an alternative or replacement for adequate carbohydrate intake in endurance athletes.[4]

What to Eat Before a Long Run

Your pre-run meal should be familiar, easy to digest and rich in carbohydrates. Examples that you can include are – oatmeal, fruit with yogurt, fruit smoothie. On days when you are having longer runs, avoid experimenting with unfamiliar foods, large quantities of fibre or heavy, high-fat meals immediately before the practice session or main marathon day as it may trigger stomach discomfort.

Your marathon nutrition routine should be practised mainly during the training sessions and not experimented on the day of marathon. Pre-marathon nutrition should be individualised as per your tolerance, preferences and gastrointestinal comfort.[5]

Nutrition during Long Runs

For longer sessions, carbohydrates during exercise help maintain energy and endurance. This is an important part of endurance nutrition and marathon training. Aim for around 60g carbohydrate per hour for exercise lasting up to 2.5 hours, and up to 90g/hour for longer sessions. Train your gut gradually to tolerate higher carbohydrate intake. Practical options include sports drinks, gels, bananas and other carbohydrate-rich foods that you have already tried.[6]

Hydration should also be personalised. Long distance running requires planning for fluids and electrolytes based on sweat rate, weather and exercise duration. A general range is 400–800 mL fluid per hour. Sodium can also be important during longer sessions, particularly beyond two hours. Avoid drinking excessively and practise your hydration plan during training.2

Recovery Nutrition after Running

Recovery is an important part of endurance nutrition during marathon training. Carbohydrates help replenish muscle glycogen, while protein supports muscle repair and recovery. Aim for around 0.8–1 g/kg/hour of carbohydrate after exercise, with at least 0.3 g/kg/hour of protein when carbohydrate intake is insufficient.[7]

Simple recovery meals include, a chicken or paneer rice bowl, eggs with toast and fruit, or yogurt with oats and fruit. Replacing fluids and electrolytes is also important after long or sweaty sessions.2

Iron, calcium, vitamin D and other micronutrients support normal body functions. Prioritise a varied, nutrient-dense diet and consider supplements when dietary intake is inadequate or a deficiency is identified.3

Common Marathon Nutrition Mistakes

Under eating while the training intensity increases is a common mistake you can make when it comes to marathon nutrition. A strong marathon runner diet should support your everyday training, not just race day. Other mistakes include avoiding carbohydrates due to fear of weight gain, eating a heavy meal before running, trying new supplements on race day and drinking without considering individual sweat needs. A balanced diet can provide many essential nutrients, while personalised advice from a sports dietitian can help identify nutritional gaps.1

Conclusion

Successful marathon preparation combines training, recovery and smart nutrition. A well-planned marathon nutrition strategy provides enough energy, carbohydrates, protein, healthy fats, fluids and micronutrients to support marathon training. Your marathon runner diet should be practical, familiar and individualised. Try different meals, gels, drinks, and hydration strategies during practice sessions so you know what works best before race day.1

The goal of running nutrition is to fuel your training and support recovery so you are ready for the demands of long distance running. Consistent marathon nutrition, appropriate marathon runner diet choices and a personalised running nutrition strategy can help you make your endurance nutrition plan work effectively on race day.

References:

[1] Tanous, D., Wagner, K.-H., Leitzmann, C., Motevalli, M., Wirnitzer, G., Rosemann, T., Knechtle, B., & Wirnitzer, K. (2022). Dietary intake of recreational endurance runners associated with race distance—Results from the NURMI Study (Step 2). Nutrients, 14(18), 3698. https://doi.org/10.3390/nu14183698

[2] Jiménez-Alfageme, R., Pino Garrone, F., Rodriguez-Sanchez, N., Romero-García, D., Sospedra, I., Giménez-Monzó, D., Ayala-Guzmán, C. I., & Martínez-Sanz, J. M. (2025). Nutritional intake and timing of marathon runners: Influence of athlete’s characteristics and fueling practices on finishing time. Sports Medicine - Open, 11, 26. https://doi.org/10.1186/s40798-024-00801-w

[3] Naderi, A., Gobbi, N., Ali, A., Berjisian, E., Hamidvand, A., Forbes, S. C., Koozehchian, M. S., Karayigit, R., & Saunders, B. (2023). Carbohydrates and Endurance Exercise: A Narrative Review of a Food First Approach. Nutrients, 15(6), 1367. https://doi.org/10.3390/nu15061367

[4] Amawi, A., AlKasasbeh, W., Jaradat, M., Almasri, A., Alobaidi, S., Abu Hammad, A., Bishtawi, T., Fataftah, B., Turk, N., Al Saoud, H., Jarrar, A., & Ghazzawi, H. (2024). Athletes’ nutritional demands: A narrative review of nutritional requirements. Frontiers in Nutrition, 10, 1331854. https://doi.org/10.3389/fnut.2023.1331854

[5] Aktitiz, S., Kuru, D., Ergün, Z., & Turnagöl, H. H. (2024). Nutritional strategies for single and multi-stage ultra-marathon training and racing: From theory to practice. Turkish Journal of Sports Medicine, 59(2), 70–87. https://doi.org/10.47447/tjsm.0807

[6] Cao, W., He, Y., Fu, R., Chen, Y., Yu, J., & He, Z. (2025). A Review of Carbohydrate Supplementation Approaches and Strategies for Optimizing Performance in Elite Long-Distance Endurance. Nutrients, 17(5), 918. https://doi.org/10.3390/nu17050918

[7] Alghannam, A. F., Gonzalez, J. T., & Betts, J. A. (2018). Restoration of Muscle Glycogen and Functional Capacity: Role of Post-Exercise Carbohydrate and Protein Co-Ingestion. Nutrients, 10(2), 253.  https://doi.org/10.3390/nu10020253