Mastering the First Marathon Fueling Strategy: A Beginner's Guide

November 22, 2025 •

4 min read

According to sports dietitians, stored carbohydrates can fuel your muscles for only about 60 to 90 minutes of running at marathon effort, making a practiced first marathon fueling strategy crucial to finishing strong. Without a plan, you risk 'hitting the wall,' a point of total exhaustion where your body runs out of available energy.

Quick Summary

A successful fueling plan for your first marathon involves carb loading in the days prior, consuming a specific breakfast, and taking in 30-60 grams of carbohydrates per hour during the race, along with adequate hydration.

Key Points

Carb-Load Correctly: Increase carbohydrate intake 1-3 days before the race by adjusting your macronutrient ratios, not just overeating.
Practice Makes Perfect: Test your entire fueling plan, including breakfast, hydration, and on-course fuel, during long training runs.
Fuel Early and Often: Start consuming 30-60 grams of easily digestible carbohydrates per hour about 30-45 minutes into the race.
Stay Hydrated and Salty: Aim for 300-600ml of fluid per hour and use electrolytes to replace lost sodium, especially in warmer weather.
Nothing New on Race Day: Stick to foods, drinks, and products that you have already practiced with and know your stomach can tolerate.
Mind the Gut: Avoid high-fiber, high-fat, and spicy foods in the 24-48 hours before the race to prevent gastrointestinal upset.
Pack Your Own: Don't rely solely on aid stations; carry your preferred fuel and hydration to ensure consistency.

The Importance of Starting Early: Training Your Gut

Many first-time marathoners focus heavily on mileage but neglect their nutrition and hydration training. Just as you train your legs, you must also train your gut to handle the specific demands of race day. This means practicing your exact fueling strategy—including your breakfast, gels, and drinks—during your longest training runs. Introducing a new food or gel on race day is a recipe for gastrointestinal distress and a miserable experience.

The Golden Rule: Nothing New on Race Day

Following this simple rule can save you from unnecessary complications. Identify the products that work best for your stomach and your taste buds during training. Stick with them exclusively for the race.

The Pre-Race Fueling Phase: Carb-Loading and Tapering

Carbohydrate loading in the 1-3 days before the marathon is a proven method for maximizing the glycogen stores in your muscles and liver. This process, paired with a tapered reduction in mileage, ensures you start the race with a full energy tank. Carb-loading doesn't mean eating until you're stuffed; it means increasing the proportion of your daily calories from carbohydrates while slightly reducing fats and fiber. You should expect a small weight gain (1-2kg) from the stored water that accompanies glycogen, a sign you've loaded correctly.

The Night Before: Light and Familiar

Your last substantial meal should ideally be at lunchtime the day before, allowing plenty of time for digestion. The evening meal should be lighter but still carbohydrate-dense. Avoid high-fiber, fatty, or spicy foods that could cause stomach upset. Excellent options include white rice, pasta with a simple tomato sauce, or a baked potato.

Race Morning Breakfast

Eat a high-carb, low-fiber breakfast 2 to 4 hours before the race. Aim for 1-4 grams of carbs per kilogram of body weight.

Oatmeal with a banana: A classic, easy-to-digest option.
Bagel with peanut butter and honey: Provides a mix of carbs and a little fat for satiety.
White toast with jam: Simple, fast-absorbing carbohydrates.

Fueling on the Course: During the Race

During the marathon, your body will constantly burn through its glycogen stores. To prevent 'bonking,' you need to replenish these stores regularly with fast-acting carbohydrates.

Your Hourly Carb Target

For first-time marathoners, a good starting point is to consume 30-60 grams of carbohydrates per hour. Some research suggests more experienced athletes can handle up to 90 grams per hour, but it is best to start conservatively. Begin fueling early, around 30-45 minutes into the race, and continue regularly every 20-40 minutes.

How to Carry Your Fuel

Running belts or vests: Securely holds gels, chews, and small bottles.
Running apparel with pockets: Many shorts and leggings have pockets specifically for nutrition.
Handheld water bottles: Some have small pouches for gels.
Aid stations: Rely on race-provided options, but confirm the brand and test it beforehand.

Comparison of Common Race Fuels


Fuel Type	Pros	Cons	Best Used For
Energy Gels	Highly concentrated carbs, easy to carry	Can cause GI issues if not taken with water, texture/taste can be off-putting	Quick energy boosts, especially in later miles
Energy Chews	Solid food texture, pre-portioned, often tasty	Requires more chewing while running, can be harder to digest than gels	Steady carbohydrate intake throughout the race
Sports Drinks	Replaces both carbs and electrolytes, easy to consume	Can be difficult to manage intake to match carb goals, risk of overhydration	Consistent fueling and hydration via aid stations

The Hydration and Electrolyte Connection

Proper hydration is just as critical as carbohydrate intake. Dehydration of just 2% of body mass can impair performance. Electrolytes, particularly sodium, are lost through sweat and must be replaced to prevent cramping and maintain fluid balance.

How to Hydrate on the Course

Aim to drink 300-600ml of fluid per hour, adjusted for weather and sweat rate. Sip regularly rather than chugging large amounts at once. If using gels, drink water to help with absorption.

Electrolyte Replacement

Electrolyte drinks or salt tablets are excellent for replenishing sodium. For example, a sports drink typically contains 250-300mg of sodium per serving, which can be supplemented with salt tablets for heavier sweaters.

Conclusion: The Final Word on Your First Marathon Fueling Strategy

Your first marathon is a monumental achievement, and a thoughtful fueling strategy is your secret weapon. The path to a strong finish begins weeks before the starting gun with proper carb-loading and extensive practice during long runs. By starting with a full tank, consistently replenishing with easily digestible carbohydrates, and staying hydrated and topped up on electrolytes, you can avoid the notorious 'bonk' and enjoy the race experience. Remember to test everything repeatedly during training, listen to your body, and never introduce new products on race day. This preparation will empower you to cross the finish line energized and accomplished. Practice your nutrition during long runs with tips from Runner's World.

Frequently Asked Questions

You should increase your carbohydrate intake to 8-12 grams per kilogram of body weight per day for 1-3 days before the race. Focus on increasing the proportion of carbs in your meals, not simply eating more total food.

Start consuming carbohydrates early, around 30-45 minutes into the race, to get ahead of glycogen depletion. Continue fueling regularly every 20-40 minutes from there.

The best fuel choice depends on personal preference and what your gut tolerates. Gels are fast-acting, chews offer a more solid texture, and sports drinks combine carbs with hydration. Practice with all options during training runs to decide what works for you.

Eat a high-carb, low-fat, low-fiber breakfast that you have practiced with 2-4 hours before the race start. Good options include oatmeal, a bagel, or white toast.

To minimize GI issues, stick to tested foods and products, avoid high-fiber or high-fat meals before the race, and pair high-carb gels with water to aid digestion. Staying properly hydrated helps absorption.

Hydration is extremely important, with dehydration leading to a significant drop in performance. It's crucial to sip fluids regularly throughout the race and to preload with electrolytes beforehand, especially in hot weather.

Yes, absolutely. Practice consuming your race-day nutrition during your long training runs. This helps your digestive system adapt and prevents unpleasant surprises on marathon day.

'Hitting the wall' is when your body depletes its glycogen stores, forcing it to use fat for fuel, which is a less efficient energy source. You can prevent it by consistently consuming carbohydrates throughout the race.