What is the best food to eat during a marathon? Fueling Strategies for Runners

October 22, 2025 •

5 min read

Studies show that runners who meet carbohydrate intake recommendations during a race are more likely to achieve faster finishing times. Therefore, understanding what is the best food to eat during a marathon is crucial for anyone aiming for peak performance and avoiding fatigue.

Quick Summary

Fueling during a marathon requires consuming easy-to-digest carbohydrates and electrolytes to replenish energy stores and replace minerals lost through sweat. Success relies on creating and practicing a personalized fueling plan, incorporating sports products or whole food alternatives.

Key Points

Prioritize Carbohydrates: Focus on easily digestible carbs for quick energy to fuel your muscles throughout the race.
Calculate Your Intake: Aim for 30–60 grams of carbohydrates per hour, adjusted for pace and individual needs, starting early in the race.
Replenish Electrolytes: Consume sodium and potassium from gels, sports drinks, or tablets to replace what's lost in sweat and prevent cramping.
Consider All Fuel Sources: Utilize commercial gels, chews, and sports drinks, or opt for natural options like bananas, dates, and honey, based on what you've practiced.
Practice, Don't Experiment: Always test your race-day fueling and hydration plan during long training runs to train your gut and avoid stomach issues on race day.
Stay Consistent: Adhere to a fueling schedule to maintain steady energy levels and avoid 'the wall,' rather than waiting until you feel depleted.

The Importance of Mid-Race Fueling

For endurance events like a marathon, your body relies primarily on stored carbohydrates, or glycogen, for fuel. However, even with perfect pre-race carb-loading, these stores are finite and can be depleted in as little as 90 minutes for some runners. The notorious experience of "hitting the wall" is a direct result of this glycogen exhaustion, leaving you feeling physically and mentally drained. Consistent mid-race fueling, therefore, becomes essential for maintaining energy levels, delaying fatigue, and sustaining your pace to the finish line.

The Science of Carbohydrate Intake

To avoid this fate, the consensus among sports nutrition experts is to consume a specific amount of carbohydrates per hour during the race. The standard recommendation is to aim for 30–60 grams of carbohydrates per hour. For experienced, faster runners who have trained their gut, higher intakes of 60–90 grams per hour may be beneficial for maximizing performance. To achieve these higher rates, some products utilize a multiple-transportable carbohydrate formula (a glucose-to-fructose ratio) to enhance absorption. The key is to start fueling early in the race, typically 30–45 minutes in, and continue with a regular, consistent intake. This prevents a significant drop in blood sugar and ensures a steady energy supply to your working muscles.

Your Fueling Options: A Comprehensive Breakdown

Runners have a variety of options to meet their hourly carbohydrate needs, ranging from specially formulated sports products to natural, whole foods. The best choice is highly personal and should be practiced extensively during training.

Sports Nutrition Products

Energy Gels: These are concentrated, high-carb pouches designed for rapid digestion and absorption. They are extremely portable and deliver a quick energy boost. Most gels contain between 20-30 grams of carbohydrates and require water to help with absorption and prevent stomach upset.
Energy Chews: Offering a similar nutritional profile to gels, chews come in a gummy, solid form. They can be easier for some runners to consume gradually and can help with palate fatigue.
Sports Drinks: Combining hydration and carbohydrates, these drinks are a convenient way to refuel. However, watch the carbohydrate concentration; too high can cause stomach issues, while too low means you need to consume more fluid to get enough carbs.

Real Food Alternatives

Bananas: A classic for a reason, one medium banana contains around 24–30 grams of easily digestible carbohydrates and electrolytes like potassium. A riper banana will have simpler sugars for faster absorption.
Dried Fruit: Options like raisins and dates are calorie-dense and portable. Two Medjool dates offer about 35g of carbs, and a small box of raisins can provide over 30g.
Honey: Squeeze packets of honey offer a natural, quick-acting source of glucose and fructose, similar to a commercial gel.
Boiled and Salted Potatoes: A favorite among ultra-runners, boiled potatoes with a sprinkle of salt provide carbohydrates and replace some sodium. They also offer a savory alternative to sweet gels.

The Critical Role of Hydration and Electrolytes

Alongside your fuel, proper hydration is non-negotiable. As you run, you lose fluids and essential electrolytes, primarily sodium, through sweat. Replacing these is crucial for preventing dehydration, regulating muscle function, and avoiding painful cramps.

Electrolyte intake can be managed through sports drinks, dissolvable tablets, or salt capsules, which are especially useful for heavy sweaters. While individual needs vary, consuming 300–600 mg of sodium per hour is a common recommendation. Hydration should be consistent throughout the race, not just when you feel thirsty, as thirst is a sign you are already dehydrated.

Creating and Testing Your Fueling Strategy

Your race day fueling plan should never be improvised. The gut can be trained just like your muscles to tolerate and absorb the carbohydrates you plan to consume.

Practice with Products: Test different products during your long training runs. This helps you identify what sits well with your stomach and what flavors you can tolerate for hours.
Simulate Race Conditions: Practice drinking from aid station cups and carrying your preferred fuel. Find out what products, if any, the race will provide ahead of time.
Establish a Schedule: Use a running watch or simple arm notes to remind yourself when to fuel, ensuring consistent intake rather than waiting for hunger or fatigue to strike.

Preventing Gastrointestinal Distress

Stomach issues, including nausea, bloating, and cramping, are common for runners. The primary cause is often dehydration, which hinders the gut's ability to absorb glucose. Other culprits include overconsuming fuel, trying new products, or eating high-fiber or high-fat foods during the run.

To minimize risk:

Stay well-hydrated from the hours leading up to the race.
Always take gels with water.
If symptoms start, slow your pace and focus on hydration.

Comparison Table: Fueling Options at a Glance


Fuel Type	Carbs/Serving	Digestion Speed	Pros	Cons
Energy Gels	20-30g	Very Fast	High energy concentration, portable, quick to consume.	Requires water, potential for stomach upset, palate fatigue.
Energy Chews	15-25g	Fast	Easy to consume gradually, can feel less aggressive on the stomach.	Can be harder to chew while breathing hard, still requires water.
Sports Drinks	30-60g+ per bottle	Fast	Combines hydration and carbs, some include electrolytes.	Can be bulky to carry, higher concentrations can cause stomach issues.
Bananas (ripe)	~30g	Fast	Natural, good source of potassium.	Can be difficult to carry and eat, not as precise on carb dosage.
Dried Fruit (Dates/Raisins)	~30-35g/small box	Fast	Natural sugars, calorie-dense.	Can be chewy and hard to eat while running, potential for GI issues with high fiber.
Honey Packets	~20-25g	Very Fast	Natural, fast-absorbing sugars.	Sticky, can be messier to handle than gels.

Conclusion

The question of what is the best food to eat during a marathon has no single answer, as it depends on individual tolerance and preferences. However, the universal strategy is to prioritize easily digestible carbohydrates and consistent hydration to fuel your body and prevent a performance-killing crash. Experimenting with different products and real food options during your training will help you develop a personalized plan that ensures you cross the finish line strong. Remember to start fueling early, stay hydrated, and never experiment with new nutrition on race day. For more in-depth information, resources from reputable running websites like Runner's World can be invaluable.

Frequently Asked Questions

Energy gels offer convenience and rapid absorption of carbohydrates, which is ideal during high-intensity running. Real foods like bananas or dried fruit can provide similar fuel but may digest slower for some. The 'best' option depends on personal preference and what you've trained your stomach to handle without GI distress.

Most runners should aim for a dose of carbohydrates every 30 to 45 minutes. This consistent intake prevents blood sugar from dropping and keeps your energy stores topped up. Set a timer on your watch to help maintain a regular schedule.

Failure to fuel adequately can lead to 'bonking' or 'hitting the wall,' which is severe fatigue and loss of energy caused by the depletion of your body's glycogen stores. This will significantly slow you down and make finishing the race very difficult.

For long runs over an hour or races in hot weather, electrolytes are necessary. Water alone is not enough, as you lose essential minerals like sodium through sweat. A lack of electrolytes can lead to dehydration, cramps, and in severe cases, hyponatremia.

If you experience an upset stomach, it's often a sign of dehydration or trying something new. First, slow your pace slightly and focus on hydration. Try sipping water or electrolyte drinks. If you suspect a specific food, avoid it. Always practice with your intended race fuel during training.

Many runners use a variety of methods to carry fuel, including running belts with small pouches, hydration vests with pockets, or shorts/tights with built-in pockets. Practice carrying your gear during training to ensure it is comfortable and doesn't chafe.

Yes, avoid high-fiber, high-fat, and high-protein foods during a marathon, as they slow digestion and can cause stomach upset. This includes many dairy products and fatty meats. Also, never try a new food or product on race day.