Key Takeaways:
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Fuel Timing: Supports long-run performance
Strategic carbohydrate intake before and during runs helps improve energy and reduce fatigue. -
Recovery Support: Extends beyond food
Supplements can fill nutritional gaps when appetite drops or training volume increases. -
Consistency: Builds race-day confidence
Testing fueling strategies early helps the body adapt and lowers the risk of surprises on race day.
Nutrition during marathon training isn’t only about carb loading the night before a race. From the early weeks of base building through long runs, speed work, tapering, and recovery, your fueling decisions play a quiet but important role. For many runners, small changes in daily nutrition or supplement use can add up over months of training, affecting energy levels, muscle preservation, and how well the body handles the demands of high mileage.
At BRL Sports, we develop products designed for real endurance athletes. Our lineup is used by runners preparing for all distances, including those building toward race day from winter base phases through to peak mileage. We’ve created resources to guide runners in choosing endurance supplements, dialing in carbohydrate timing, and avoiding common fueling errors so they can train smarter, not just harder.
In this guide, we’ll walk through what marathon training nutrition looks like at each stage, from early training to race day, and how to build a fueling strategy that supports your performance goals from start to finish.
Nutrition Foundations for Marathon Training
Building a strong nutrition foundation early in training makes it easier to adapt as your mileage increases. Even if your runs are still short, your body is already adjusting to new demands, and what you eat supports that adaptation over time.
Marathon training nutrition should focus on providing enough energy to fuel workouts, support recovery, and prevent fatigue accumulation. It also helps regulate hormone balance, muscle function, and immune health during high training loads.
Some of the most important areas to focus on include:
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Total calorie intake
As mileage increases, so do your calorie needs. Under-eating may lead to performance plateaus or increased risk of injury. -
Macronutrient balance
Carbohydrates fuel your runs, protein supports muscle recovery, and fats help with long-term energy and hormone support. -
Meal timing
Eating within 60 minutes post-run can help with muscle repair. Pre-run meals should be easy to digest and high in carbohydrates. -
Hydration
Training with low fluid intake can slow recovery and make runs feel harder than they need to. -
Micronutrient support
Nutrients like iron, magnesium, and B vitamins are key to energy metabolism and muscle function.
These habits matter even in early phases of training. If you’re starting during colder months, this winter marathon training guide also covers seasonal considerations like hydration and temperature regulation.
What to Eat During Base Building and Long Runs
As your mileage increases, what you eat before, during, and after your long runs becomes more important. Fueling properly in this stage can help you maintain energy, reduce soreness, and support consistent progress week after week.
Supplements for marathon training are not a replacement for food, but they can support your routine by filling gaps in energy, recovery, or hydration. This becomes helpful when appetite is low or meals are harder to plan around training.
Pre-Run Fueling
Before a long run, the goal is to eat something that provides carbohydrates and sits well in your stomach. Most runners benefit from a light meal or snack 60 to 90 minutes before heading out. Some prefer liquids if eating solid food that early feels uncomfortable.
During the Run
Once your runs go beyond 75 to 90 minutes, taking in carbohydrates during the effort becomes more important. Gels, chews, sports drinks, and other portable carbs can help delay fatigue. Hydration with electrolytes may also support longer efforts, especially in heat or humidity.
Post-Run Recovery
After your run, refueling with a mix of carbs and protein can help your body start repairing muscle tissue and replenishing glycogen. Aim to eat within an hour of finishing your long run, even if it’s just a small meal or shake.
Where Supplements Fit In
This is often the stage when runners start experimenting with mid-run fueling options and recovery aids. Carbohydrate drinks or energy gels are common, but daily-use options like amino acids or adaptogens may also support recovery from long efforts. You’ll find a full range in our endurance supplements collection to explore what fits your style of training.
Creating a Marathon Fueling Strategy That Scales
A marathon fueling strategy should be flexible enough to evolve with your training. What works at 10 miles may not be enough for 16 or 20. As long runs get longer and intensity builds, your energy demands shift too. Building a simple plan early can help reduce guesswork as your body starts to need more.
The foundation of any good marathon fueling strategy includes:
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Consistent carbohydrate intake
Carbs are the primary energy source for distance running. Most runners do best when they fuel regularly on long runs and during races. -
Mid-run fueling practice
Taking in calories during long efforts helps your gut get used to absorbing fuel while running. This is a skill that requires repetition. -
Portable fuel options
Gels, chews, sports drinks, and powders each have different textures and absorption rates. Testing several early in training helps you choose what works best. -
Hydration timing
Small, frequent sips are easier to tolerate than large gulps. Matching fluid intake to sweat loss is also more effective than guessing. -
Simple tracking
Keeping a basic log of what you eat before, during, and after key runs can reveal patterns and help you adjust over time.
For runners unsure how much to take in during a race, this guide on how many carbs per hour during a race can help outline general targets and individual adjustments.
Your Marathon Nutrition Plan for Peak Training Weeks
As you enter peak training weeks, your mileage climbs, long runs stretch further, and your need for reliable nutrition becomes even more important. This stage is when small habits make the biggest difference, especially in helping you recover between sessions and stay strong during back-to-back efforts.
A marathon nutrition plan at this point usually shifts to include more total calories, higher carbohydrate intake, and more structured pre- and post-run meals. Protein also becomes more important to support muscle preservation and repair. Runners often find that hydration timing and consistency matter more during these weeks, particularly if training includes speed work or back-to-back long sessions.
Supplements may also start to play a more active role, especially when appetite drops or training volume makes meal prep harder to manage. Some runners add electrolytes, recovery drinks, or easy-to-digest carbs during this phase to help simplify fueling around longer runs.
If you’re looking to better match your carbohydrate needs to this stage of training, the guide on carbohydrate use in marathon running offers helpful insight into how to time and scale intake based on workout demands.
Race Week and Race Day Nutrition Tips
In the final week before your marathon, the goal is to support your energy levels without overcomplicating your routine. This is not the time to experiment, but to stick with what has worked during training while making a few strategic adjustments to help you feel ready at the start line.
Keep Meals Familiar and Balanced
Race week meals should feel easy to digest and familiar. Most runners shift toward higher carbohydrate intake in the three days leading up to the event, often referred to as carbohydrate loading. This can help top off glycogen stores and reduce early fatigue on race day.
Stay Ahead of Hydration
Drink water regularly throughout the week, and consider adding electrolytes if your race is in a warmer climate or if you know you sweat heavily. Avoid overhydrating or drinking large volumes all at once. Small amounts spaced throughout the day are usually more effective.
Plan Your Morning Routine
On race day, eat a simple breakfast two to three hours before the start. Choose foods you’ve practiced with during training and avoid anything new. Some runners also take a small carbohydrate boost 30 minutes before the gun goes off.
Use Only Familiar Fueling Products
Stick with the same gels, drink mixes, or chews you’ve used during long training runs. Introducing something new on race day is risky, especially under physical stress. This is where the best supplements for marathon training can really help. Whether you're using a carb-electrolyte blend or a simplified energy formula, it's best to rely on options your body has already responded well to.
Common Mistakes That Affect Marathon Nutrition
Even well-prepared runners can run into nutrition issues during marathon training. Most of these are easy to avoid once you know what to watch for, and many come down to not practicing your plan early enough.
One common issue is under-fueling during long runs. Waiting too long to take in calories or skipping them altogether can lead to low energy, poor recovery, and a harder time finishing key sessions. The same goes for hydration. Relying on thirst or not drinking during long efforts often leaves runners playing catch-up later in the day.
Another area runners overlook is race week nutrition. Changing your meals, adding new supplements, or increasing fiber too close to race day can lead to digestive discomfort or unexpected problems during the race. Sticking with foods and timing you've practiced can help reduce these risks.
If you're unsure where your fueling might be falling short, this article on nutrition mistakes runners make breaks down the most common issues seen in training and racing, with simple ways to adjust.
Final Thoughts on Fueling for 26.2 Miles
Marathon training nutrition is not about chasing the perfect formula. It’s about finding what works for your body, your schedule, and your training goals. The earlier you start practicing with fueling strategies and paying attention to your recovery needs, the easier it becomes to adjust as race day gets closer.
Food will always play the most important role in fueling your runs, but supplements can help support consistency, recovery, and convenience, especially when training volume increases or appetite changes. With the right plan in place, nutrition becomes something that supports your progress instead of something you have to manage last minute.
Every runner responds differently, so starting small, tracking what works, and being open to adjustments is what makes your plan sustainable over the full marathon cycle.
Frequently Asked Questions About Marathon Training Nutrition
Do I need to carbo-load for every long run?
Not necessarily. Carbo-loading is more useful for race day or your longest efforts. For regular long runs, a steady carb intake the day before is usually enough.
How many grams of carbs do marathoners need per day?
Many runners aim for 5 to 7 grams of carbohydrates per kilogram of body weight during peak training, depending on volume and intensity.
Can I train my gut to handle more fuel during runs?
Yes. Practicing with gels, chews, or carb drinks during long runs can help your body absorb more fuel without discomfort.
Is caffeine useful for marathon runners?
For some, caffeine may improve focus and reduce perceived effort. Always test it during training first to gauge your tolerance.
What should I avoid eating before a long run?
High-fat, high-fiber, or unfamiliar foods may lead to digestive discomfort. Stick with simple meals you’ve already used successfully.
Is fasted running helpful during marathon training?
Some runners try it early in a cycle, but it’s not ideal for peak long runs. Fueling properly tends to support better performance and recovery.
What are good recovery foods after a long run?
Look for a mix of carbs and protein. Popular options include smoothies, yogurt with fruit, or rice and eggs.
Do I need to take electrolytes every day?
Not necessarily. On hotter days or during longer runs with heavy sweat loss, electrolytes may be more helpful than plain water alone.
Should I eat during short runs too?
Most runners do not need fuel for runs under 75 minutes. Beyond that, adding carbs can help maintain energy and delay fatigue.
Are natural foods better than sports supplements?
Whole foods work well when available, but supplements offer consistency and convenience when time, appetite, or conditions make meals harder to manage.
Sources:
- Rubén Jiménez-Alfageme, Garrone, F. P., Rodriguez-Sanchez, N., Romero-García, D., Sospedra, I., Giménez-Monzó, D., César Iván Ayala-Guzmán, & José Miguel Martínez-Sanz. (2025). Nutritional Intake and Timing of Marathon Runners: Influence of Athlete’s Characteristics and Fueling Practices on Finishing Time. Sports Medicine - Open, 11(1). https://doi.org/10.1186/s40798-024-00801-w
- Lima, F. F., Beck, H. A. D. P., & Maynard, D. da C. (2025). A importância da ingestão dos carboidratos por atletas de alta performance em exercícios de endurance. Research, Society and Development, 14(4), e1614448597. https://doi.org/10.33448/rsd-v14i4.48597
- 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
