Fueling for Success: A Guide to Marathon Nutrition
You’ve put in the miles, nailed your workouts, and tapered like a pro—now don’t let poor nutrition derail your marathon performance! Proper fueling before, during, and after your race can make the difference between feeling strong through mile 26.2 or hitting the dreaded wall.
In this post, we’ll break down the essentials of marathon nutrition, including pre-race fueling, race-day strategies, and post-race recovery. Plus, we’ll cover how to practice fueling during training to ensure your stomach is as prepared as your legs on race day.
Many of these insights come from Featherstone Nutrition, a trusted source for endurance fueling strategies. Dietitian Megan Featherstone works with runners of all levels to fine-tune nutrition for performance and recovery. Let’s dive in!
Pre-Marathon Nutrition: The Foundation of Success
The Week Before: Carbs Are Your Best Friend
Carbohydrate loading isn’t about stuffing yourself with pasta the night before. Instead, it’s a gradual process that should start about 3–4 days before race day. According to Featherstone Nutrition, you should aim for 3.5 to 5.5 grams of carbs per pound of body weight daily leading up to the race. That means increasing carbs while slightly decreasing protein and fat intake to make room for extra glycogen storage.
Hydration Matters
Hydration isn’t just about drinking water—it’s about balancing electrolytes. In the days leading up to your race, aim for 80–100 oz of fluid per day, and consider adding electrolytes like sodium to prevent cramps and dehydration (especially if it’s a warm race). Featherstone recommends products like Nuun, Liquid IV, or Skratch for runners who need extra support.
The Night Before: Keep It Simple
Stick to low-fiber, high-carb meals the night before. Avoid heavy sauces, fried foods, and too much fiber to prevent GI distress on race morning. A good pre-race dinner might include white rice, potatoes, a simple protein like chicken or tofu, and a bit of fat (think olive oil, not a greasy burger).
Race Morning: Setting Yourself Up for a Strong Start
Timing Your Breakfast
Your final meal should be 2–3 hours before race time, giving your body enough time to digest. Featherstone suggests 100 grams of carbohydrates for a solid pre-race meal, such as:
Bagel with peanut butter and banana
Oatmeal with honey and berries
Toast with jam and a sports drink
Pre-Race Hydration
Start sipping 16–20 oz of fluids when you wake up and top off with 8 oz of a sports drink or electrolyte mix 30 minutes before the race.
Fueling During the Marathon: Avoiding the Wall
The 45-Minute Rule
One of the biggest mistakes runners make is waiting too long to fuel. Your glycogen stores start depleting within 45–60 minutes, so it’s crucial to start fueling early. A general guideline is:
30–60g of carbohydrates per hour for runs under 3 hours
60–90g of carbohydrates per hour for longer races
Gels, Chews, and Whole Foods: What’s Best?
According to Featherstone, the best fueling option is the one your stomach tolerates best. Options include:
Gels (GU, Maurten, Huma, etc.) – Quick energy, easy to carry.
Chews (Clif Bloks, Honey Stinger, etc.) – Good alternative to gels for a slower release of carbs.
Sports Drinks (Gatorade Endurance, Tailwind, etc.) – Provides both fluids and carbs in one.
Real Food (bananas, dates, rice cakes, etc.) – Great for those with sensitive stomachs.
Most runners need a gel or equivalent every 30–45 minutes to stay fueled. Don't wait until you feel tired—by then, it's too late!
Electrolytes and Hydration Strategy
Water alone isn’t enough, especially for long races. Featherstone recommends drinking 4–8 oz of fluid every 15–20 minutes and making sure you’re getting 300–500 mg of sodium per hour (especially in warm conditions).
Practicing Nutrition During Training Runs
You wouldn’t try a new pair of shoes on race day, and the same goes for fueling. Your long runs should be used to practice your nutrition plan so that your stomach can adjust to digesting carbs while running.
How to Train Your Gut
Start by taking a gel every 45 minutes and gradually increase intake to one every 30 minutes.
Test different brands of gels, chews, and drinks to find what works best for you.
Simulate race conditions by fueling at the same times you plan to on race day.
Featherstone emphasizes that you can train your gut to tolerate more carbs, which can help you perform better in the marathon. If you struggle with GI issues, try switching to liquid calories like Maurten or Skratch Superfuel.
Common Fueling Mistakes and How to Fix Them
Skipping Fuel Early in the Race: Many runners wait too long to start fueling, which leads to energy crashes. Start within the first 30–45 minutes, even if you don’t feel hungry.
Trying Something New on Race Day: Never use a gel, drink, or fueling strategy you haven’t tested before. Your gut needs time to adjust to new products.
Overhydrating or Underhydrating: Drinking too much water without electrolytes can lead to hyponatremia, while drinking too little leads to dehydration. Find a balance based on sweat rate and temperature.
Post-Marathon Recovery Nutrition
The Golden 30-Minute Window
After crossing the finish line, your body needs carbs to replenish glycogen and protein to repair muscle. Aim for 3:1 carb-to-protein ratio, such as:
Chocolate milk + banana
Protein smoothie with oats and berries
Rice + beans + avocado
Rehydration and Electrolytes
Continue hydrating throughout the day with electrolytes and fluids to replace what was lost during the race.
Conclusion
Marathon fueling isn’t just about race day—it’s about practicing in training, fine-tuning your strategy, and listening to your body.
Key takeaways:
✅ Start fueling early and often during the race
✅ Practice your nutrition plan during training runs
✅ Carb load properly the week before
✅ Hydrate with electrolytes, not just water
✅ Recover with carbs + protein after the race
Have a fueling strategy that works well for you? Share your experience in the comments!
For more expert guidance on endurance fueling, check out Featherstone Nutrition.
