Nutrition Diet: What marathon runners can eat during a race?

Faster marathoners can benefit from consuming up to 90 grams of carbohydrates per hour, but figuring out what marathon runners can eat during a race? is a highly personalized process. An effective nutrition strategy is just as vital as physical training for sustained performance over 26.2 miles.

Quick Summary

This comprehensive guide details the science behind in-race fueling, covering optimal carbohydrate targets, hydration, electrolyte needs, and the different fueling options like gels, chews, and real food for endurance running. Practical strategies for timing nutrition and avoiding gastrointestinal issues are also included.

Key Points

• Start fueling early: Begin consuming carbohydrates 30-45 minutes into the race, not when you feel tired, to prevent glycogen depletion.

• Target 30-60g carbs/hour: Aim for a consistent hourly intake of carbohydrates, using a combination of gels, chews, or real food options.

• Don't forget electrolytes: In addition to water, replace lost sodium and other minerals with sports drinks, chews, or salt tablets, especially in hot weather.

• Practice your plan: Never try a new fuel strategy or product on race day. Use your long training runs as a rehearsal for your exact nutrition plan.

• Consider real food: For those with sensitive stomachs or taste fatigue from gels, options like bananas, dates, or boiled potatoes can be effective alternatives.

• Use caffeine strategically: A dose of caffeine in the later miles can help reduce fatigue and increase focus, but test your tolerance during training.

The Science of In-Race Fueling

For a marathoner, the body relies primarily on stored carbohydrates, known as glycogen, for energy. These stores are limited and can be depleted within 60 to 90 minutes of high-intensity running, leading to "the bonk"—a state of profound fatigue and exhaustion. This is why replenishing carbohydrates during the race is non-negotiable for anyone aiming to perform well. The goal is to ingest external carbohydrates to spare muscle glycogen and maintain blood sugar levels, which in turn preserves muscle function and cognitive focus.

Experts typically recommend consuming between 30 to 60 grams of carbohydrates per hour of running, starting 30 to 45 minutes into the race. For elite or well-trained athletes, this can be pushed to 90 grams per hour or more, but this requires "gut training"—acclimating the digestive system to higher loads during training. High rates of carbohydrate intake (90g+/hr) often require a blend of glucose and fructose to utilize multiple absorption pathways in the gut, minimizing the risk of stomach issues.

Fueling Options: Gels vs. Real Food

Marathon runners have a variety of fuel options to choose from, each with distinct pros and cons. The best choice is often a personal preference honed through careful training.

Energy Gels and Chews

Energy gels and chews are the most popular and convenient fueling option for many runners. They offer a concentrated source of carbohydrates in a small, easy-to-carry package. Many brands offer a variety of flavors and formulations, including those with added electrolytes and caffeine.

Key characteristics of gels/chews:

• Convenience: Compact, lightweight, and easy to carry in running shorts or belts.
• Rapid Absorption: Formulated for quick digestion, delivering a fast energy boost.
• Consistency: Some runners experience flavor fatigue or find the texture unpleasant over time.

Real Food Options

For some runners, heavily processed sports nutrition can cause digestive distress. "Real food" options provide carbohydrates in a more natural, digestible form. These are particularly popular with ultra-marathoners or runners who prefer a savory option later in the race.

Popular real food choices include:

• Bananas: Provides easily digestible carbs and potassium.
• Dates: A concentrated source of natural sugar.
• Boiled, Salted Potatoes: Offers carbs and sodium, perfect for savory cravings.
• Raisins: Studies show they can be as effective as chews.

Feature	Energy Gels/Chews	Real Food Options (e.g., bananas, dates)
Convenience	Excellent: compact, single-serving, easy to carry.	Variable: can be bulky, requires prep and packaging.
Digestion Speed	Fast: designed for rapid absorption during exercise.	Slower: contains fiber, requiring more digestion.
Nutrients	Focused on carbohydrates and electrolytes; fewer micronutrients.	Contains vitamins, minerals, and antioxidants from whole sources.
Taste	Can lead to palate fatigue due to sweetness.	Offers a variety of natural flavors to prevent taste burnout.
Cost	Higher cost per serving.	More budget-friendly per gram of carbohydrate.

Hydration and Electrolytes: More Than Just Water

Hydration is paramount for performance and safety during a marathon. Even mild dehydration can impair your cardiovascular function, increase body temperature, and lead to muscle cramps. In addition to water, replenishing electrolytes—especially sodium—is critical, as these are lost through sweat. A lack of sodium can lead to hyponatremia, a dangerous condition caused by low blood sodium levels.

Your Hydration Plan

• Drink regularly: Aim for regular, small sips of fluid every 15-20 minutes, rather than chugging large amounts at once.
• Use sports drinks or tablets: For runs over an hour, or in hot conditions, a sports drink or electrolyte tablet can help replace lost salts and provide additional carbohydrates.
• Know your sweat rate: Experiment in training to determine your personal sweat rate and hydration needs. You can weigh yourself before and after a long run to get an estimate.

Crafting Your Marathon Race Day Strategy

Timing Your Fuel

Consistency is key. Don't wait until you feel tired to start fueling. Begin with your first gel, chew, or real food snack 30-45 minutes into the race and continue at regular intervals, typically every 30-40 minutes. Setting an alarm on your running watch can help remind you, especially in the excitement of a race.

The Role of Caffeine

Caffeine can be a potent performance enhancer, reducing the perception of fatigue and pain, and increasing alertness. Many marathoners strategically incorporate caffeine late in the race, typically after mile 18, to get a boost for the final push.

• Timing: Take a caffeinated gel or chew about 45-60 minutes before you need the peak effect, as absorption takes time.
• Caution: Practice with caffeine during training runs, as individual tolerance varies greatly. Excessive caffeine can cause jitters, heart palpitations, or stomach issues.

Avoiding Gastrointestinal (GI) Distress

Stomach upset is a major concern for marathoners. It's often caused by eating the wrong foods or timing fueling incorrectly.

• Train your gut: Practice your exact race-day nutrition plan during your longest training runs. Your digestive system can be trained to tolerate fuel during exercise.
• Avoid certain foods: On race day and in the hours leading up to it, avoid foods high in fiber, fat, and protein, as these slow digestion and can cause discomfort. Dairy and excessive fructose can also be triggers for some.
• Don't overdo it: Taking in too much concentrated carbohydrate at once, especially without enough water, can lead to cramps and diarrhea. Dilute gels with water at aid stations.

Making Your Own Marathon Fuel

Creating your own fuel can be cost-effective and beneficial if you prefer natural ingredients or need to avoid specific triggers. Here are a couple of popular DIY recipes:

• Banana-Date Puree: Blend mashed ripe banana with soaked dates, a pinch of salt, and a little water until it reaches a desired, squeezable consistency.
• Salty Sweet Potato Pouch: Puree steamed or roasted sweet potato with water and a dash of salt for a savory fuel option.

Homemade fuel can be carried in reusable pouches or small zip-top bags. Always test homemade fuel thoroughly in training to ensure it works for you.

Conclusion

A successful marathon fueling strategy is a culmination of careful planning, consistent practice, and personalized refinement. The best plan is the one you have rehearsed thoroughly during your training long runs and know your body can tolerate. Start with a benchmark of 30-60 grams of carbohydrates per hour, combine it with a consistent hydration plan that includes electrolytes, and experiment with different fuel types—from gels and chews to real foods and homemade options. Remember to listen to your body, avoid introducing anything new on race day, and tailor your nutrition to your individual needs and the race conditions. Ultimately, a smart nutrition diet will give you the energy and confidence to finish strong.

Runner's World offers more expert advice on tailoring your fueling plan.

Frequently Asked Questions

How many gels should a marathon runner take?

Most runners should aim for 1 to 2 energy gels per hour to meet the recommended 30-60g of carbohydrate intake, based on the gel's carbohydrate content. Heavier or elite runners may need more, up to 3 gels per hour.

Is it better to use gels or real food during a marathon?

The best option depends on individual tolerance and preference. Gels are convenient and fast-acting, while real food can be easier on the stomach for some and provides additional nutrients. Many runners use a mix of both.

When should I start fueling during a race?

You should start fueling early, within the first 30-45 minutes of the race, to get ahead of glycogen depletion. Do not wait until you start feeling tired.

What can I eat during a marathon to avoid stomach cramps?

To avoid stomach cramps, practice your nutrition strategy in training and avoid high-fiber, high-fat, and high-protein foods before and during the race. Ensure you are properly hydrated with water and electrolytes, as dehydration can cause GI issues.

Should I take caffeine during a marathon?

Caffeine can be beneficial in the later stages of a marathon by reducing perceived effort. If you plan to use it, test it during training runs to determine your sensitivity and the optimal timing, typically an hour before you need the effect.

How important are electrolytes during a marathon?

Electrolytes are very important, especially sodium, which is lost through sweat. Replenishing them prevents muscle cramps and helps maintain fluid balance, reducing the risk of hyponatremia.

Are homemade fuels effective for marathon runners?

Yes, homemade fuels can be effective and are often preferred by runners who want to control ingredients or avoid processed foods. Popular options include purees made from dates, bananas, or sweet potatoes.