Running a marathon is as much about strategy as it is about stamina—and what you eat in the days leading up to race day can dramatically influence how you perform and how you feel. A solid pre-marathon nutrition plan ensures your glycogen stores are full, your digestive system is settled, and your energy levels are steady from start to finish.

But pre-race nutrition is often misunderstood. Many runners either under-fuel, overdo it on carbs, or experiment with new foods too close to race day. This guide will walk you through everything you need to know to approach your next marathon with confidence—from one month out to the final breakfast before the gun goes off.

The Basics: What Pre-Marathon Nutrition Is All About

At its core, your pre-marathon nutrition plan should aim to:

• Maximize glycogen storage in your muscles and liver
• Avoid gastrointestinal discomfort on race day
• Maintain hydration and electrolyte balance
• Provide familiar, digestible fuel at the right times

This isn’t the time for trendy diets or radical changes. You’re not trying to lose weight or “cleanse”—you’re preparing your body for a 42.2-kilometer effort that demands endurance, efficiency, and resilience.

One Month Before the Race – Dial In the Routine

In the final month of marathon training, your weekly mileage is high and your body is under stress. This is the time to focus on consistency and recovery. Key guidelines include:

• Eat enough: You may be burning more than you realize. Skipping meals leads to fatigue, poor recovery, and even injury.
• Balance macros: Focus on whole foods with a healthy balance of complex carbohydrates, quality protein, and healthy fats.
• Practice race nutrition: Use your long runs to test pre-run meals and during-run fuel (gels, bananas, sports drinks) to train your gut.
• Hydrate daily: Don’t wait until race week to focus on fluids. Keep water intake consistent and consider adding electrolytes after long sessions.

This phase is also ideal for identifying food sensitivities. If dairy, high-fiber vegetables, or spicy foods give you issues, begin phasing them out of your diet on long-run days.

Two Weeks Out – Begin Taper and Eat Strategically

As your mileage drops during the taper, your energy requirements will decrease slightly, but not dramatically. Many runners make the mistake of reducing calories too much, which can lead to depleted glycogen stores on race day.

Focus on the following:

• Stick to familiar foods: Now is not the time to try new recipes or snacks.
• Don’t reduce carbs yet: You’re training less, but your body still needs fuel to recover and replenish.
• Watch fiber and fat: Start slightly reducing high-fiber vegetables and heavy meals that may sit in your stomach too long.
• Time your meals: Avoid eating too late at night. Try to keep your meals steady, light, and carb-forward.

This period is more about maintaining balance than making changes. Listen to your body. Stay fueled, hydrated, and rested.

Week of the Race – Carb-Loading Begins

The final 3–4 days before race day are when carb-loading takes center stage. The goal is to maximize glycogen storage so you start the race with full energy reserves.

What carb-loading is not: stuffing yourself with pasta at every meal. What it is: increasing your carb intake from roughly 50% of your daily calories to around 70–75%, while keeping your total calories steady or only slightly elevated.

Good carbohydrate sources include:

• White rice
• Pasta (without heavy sauces)
• Potatoes and sweet potatoes
• Bananas
• Low-fiber cereal and toast
• Fruit smoothies
• Oats and low-fat granola

At the same time, reduce:

• High-fat meals (they slow digestion)
• High-fiber foods (to avoid race-day GI issues)
• Alcohol and excessive caffeine (they dehydrate)

Your protein and fat intake can decrease slightly during this time to make room for the higher carb percentage.

Hydration Strategy

Don’t overhydrate in the last few days—it can lead to sodium imbalance. Instead, drink consistently throughout the day, aiming for clear to light-yellow urine. Add an electrolyte tablet to one or two of your water bottles each day to maintain sodium, potassium, and magnesium balance.

Foods like soups, fruit juices, and watery fruits (like watermelon or oranges) are great for maintaining hydration while also contributing to your carb intake.

Day Before the Marathon – Keep It Simple

You’ve done the work. The day before the race should be about rest, light movement (a 20-minute shakeout run is ideal), and digestion-friendly meals.

Best practices include:

• Stick to bland, low-fiber meals: white rice, plain pasta, baked potatoes, toast
• Keep meals small and frequent: large meals can overload your digestive system
• No heavy sauces, red meat, or high-fat dairy
• Avoid unfamiliar restaurants or exotic cuisine—go with what your stomach knows

For hydration, drink small amounts throughout the day rather than guzzling water all at once. Stop drinking heavily about 2 hours before bed to avoid overnight bathroom trips.

Race Morning – The Final Meal

What you eat before the race can make or break the first 10 kilometers. Ideally, your pre-race meal should happen about 2.5 to 3 hours before the start and contain 100–150 grams of easily digestible carbs.

Options include:

• Oatmeal with honey and banana
• Toast with jam and a small amount of nut butter
• White rice and eggs
• Low-fiber cereal with almond milk
• Rice cakes with banana slices

Pair your meal with water or a sports drink and, if you’re used to caffeine, a small coffee about 90 minutes before go-time.

Avoid high fiber, high fat, and high protein. These slow digestion and increase the risk of GI distress on the course.

If your stomach feels uneasy, have a small carb snack (like a banana or energy chew) 30 minutes before the start to top up glycogen stores.

During the Race – Fuel On the Move

Though not technically “pre-marathon,” during-race nutrition is part of your preparation. If your race will last more than 90 minutes, plan to consume 30–60 grams of carbohydrates per hour starting around 45 minutes into the race.

Practice this during your long runs using energy gels, sports drinks, or other carb sources. The goal is to avoid the infamous “wall” caused by glycogen depletion.

Never try a new gel or food for the first time on race day. Your gut needs to be trained just like your legs.

Common Mistakes to Avoid

• Overeating the night before: A heavy stomach can ruin sleep and race-day comfort.
• Skipping breakfast: Even if nerves kill your appetite, eat something small and carb-based.
• Trying new foods or supplements last-minute: If it’s not in your training, it doesn’t belong in your race.
• Forgetting electrolytes: Especially in warm or humid races, electrolyte imbalance leads to cramping and fatigue.
• Relying solely on race aid stations: Bring your own tested fuel just in case.

Final Thought

A successful marathon starts long before the starting line—with consistent, thoughtful fueling. When your nutrition plan is built around simplicity, familiarity, and timing, your body will respond with steady energy, fewer issues, and a stronger performance. The secret isn’t in some magical food or supplement—it’s in consistency, awareness, and knowing what works for you.