What to Eat Before a Marathon: My Complete Fueling Strategy (7/6)

*7/6/26 and always evolving* Most marathon nutrition advice sounds the same. Eat more carbs. Stay hydrated. Don't try anything new. All of that is true, but it doesn't tell you exactly what to eat, how much to eat, or why. I'm not a professional runner. I'm a digital professional who spends most of the day behind a desk [building websites](https://www.michaelbakerdigital.com). I went from a desk job to running a 3:25 marathon through consistent training, smart nutrition, and a fueling strategy refined over hundreds of training miles. Now I'm chasing a 3:10. Everything in this guide has been tested during long runs, tempo runs, and race day. Nothing here comes from theory. It's the exact system I use before every marathon. ## Your Marathon Doesn't Start on Race Morning Most runners focus on breakfast. I focus on the 48 hours before the race. Your muscles and liver store carbohydrate as glycogen. Full stores hold roughly 1,800 to 2,000 calories, about 450 to 500 grams of carbohydrate. At race pace you burn 100 to 120 calories per mile, so even a full tank only carries you 15 to 18 miles. After that your body shifts to fat, fat can't convert fast enough to hold pace, and you hit the wall. I hit it at mile 22 in New York City. The last 4 miles were a grind I'll never forget. The wall is not inevitable. It's the predictable result of starting with partially depleted glycogen or failing to refuel during the race. Both are within your control. By race morning, I want my glycogen stores completely topped off so my muscles have the maximum amount of carbohydrate available when the gun goes off. Race morning simply finishes the process. ## Why Carbohydrates Win Your body stores plenty of fat, even if you're lean. The problem is speed. Fat cannot be converted into energy quickly enough to sustain marathon race pace. Carbohydrates can. That's why I prioritize carbohydrates before every marathon. The goal isn't to avoid fat forever. The goal is to begin the race with as much stored glycogen as possible. ## My 48 Hour Carb Load About two days before the marathon, I gradually shift my diet toward carbohydrates. My daily targets: - 500 to 600 grams of carbohydrates (a good general rule is 3 to 4 grams per pound of bodyweight per day) - 120 to 150 grams of protein, from lean sources only - Fat as low as reasonably possible - Reduced fiber - Water and electrolytes consistently throughout the day Fat slows digestion and crowds out carbohydrate intake. Cutting it is what lets you hit these carb numbers without a huge calorie surplus. Any short-term weight gain should come from glycogen and water, not stored fat. Each gram of glycogen binds about 3 grams of water, which is also why electrolytes matter during the load. I don't eat junk food simply because it's high in carbohydrates. I choose foods I know digest well because I've practiced with them during training. ## What I Actually Eat A quick note on my food philosophy before the list. I believe in single ingredient, real foods as often as possible. I cut out as much processed food as I can, and I buy organic when possible. Maple syrup is one ingredient. Honey is one ingredient. Rice, potatoes, bananas, dates. The shorter the ingredient list, the more it earns a place in my fueling. **Breakfast:** - Plain bagels - Pure maple syrup - Raw honey - Bananas - Blueberries - Cinnamon - Water **Meals:** - White rice - Potatoes - Sweet potatoes - Oatmeal - [Low fat granola](/recipes/my-ultra-light-endurance-granola-for-marathon-carb-loading) - Fresh fruit - Lean chicken breast - Homemade chicken bone broth **Snacks:** - Dates - [Homemade granola](/shop/p/endurance-granola-ultimate-marathon-carb-loading-fuel) - Bananas - Applesauce - Pretzels **Dessert:** - Enjoy Life Dark Chocolate Chips in moderation Nothing is fancy. Everything has already proven itself during training. One staple worth calling out: bone broth. It delivers lean collagen protein for tendons and connective tissue, plus sodium, potassium, and magnesium to support fluid balance while you load. It's light, fast-digesting, and perfect the night before when you want nutrient density with minimal digestive load. My anchor meal during every [carb load](/courses/how-to-run-marathon/diet-and-fueling) is a simple breakfast soup: 2 cups chicken bone broth, 1 cup cooked white rice, 2 oz shredded chicken breast, sea salt. About 347 calories and 65 grams of carbs. ## My Homemade Marathon Gel Commercial gels work. I simply prefer making my own. Each batch contains: - 1/2 maple syrup - 1/2 raw honey - 1/2 teaspoon sea salt That's it. The honey naturally provides both glucose and fructose. Maple syrup contributes additional carbohydrate. Sea salt replaces sodium. Freeze it in a soft flask overnight and take 1 to 2 tablespoon pulls per fueling stop. It costs less than commercial gels and has fueled countless long runs. ## Understanding Glucose and Fructose This was one of the biggest breakthroughs in my marathon nutrition. Glucose and fructose don't use the same absorption pathway. Glucose uses the SGLT1 transporter, good for about 60 grams per hour on its own. Fructose uses the GLUT5 transporter, an entirely separate route processed by the liver. Because they use different transporters, combining them allows your body to absorb more carbohydrate than relying on glucose alone. That's why elite runners can consume 90 to 120 grams of carbohydrates per hour without overwhelming a single transport system, and why my gel, my dates, and my carb-load food list all pair the two. ## Race Morning I eat about three hours before the start. My breakfast usually provides around 100 to 150 grams of carbohydrates. Typical breakfast: - 2 plain bagels - Honey - Pure maple syrup - 1 banana - Water - Electrolytes About 30 minutes before the start I take one final top-up: 2 to 4 tablespoons of maple syrup and a banana. This loads the liver and primes your bloodstream with available glucose right as you start running. Nothing changes. No restaurants. No buffet. No "cheat meal." If I haven't eaten it during training, I won't eat it before a marathon. ## Hydration Hydration starts during carb loading, not at the starting line. I drink steadily throughout the day and include electrolytes instead of relying only on plain water. My race-day hydration is a homemade electrolyte drink: 1 NUUN tablet, 1 teaspoon sea salt, 1 tablespoon honey, juice of half a lemon, and water in a 14 oz collapsible flask, frozen solid overnight. I carry it frozen in my compression shorts pocket. It thaws gradually during the race, the cold makes it easy to actually drink, and the frozen state forces slow, controlled sips instead of early over-drinking. My goal is simple. Start hydrated. Not overhydrated. ## During the Marathon I begin fueling early. Waiting until you feel tired is already too late. By the time you feel the drop, your glycogen is already depleted. Throughout the race I aim for approximately 90 to 120 grams of carbohydrates per hour using a clean 2.5-mile pattern I've practiced throughout training: - Start line: 2 to 3 Clif Bloks in my mouth, dissolving slowly for a steady glucose trickle - Miles 2.5, 7.5, 12.5, 17.5, and 22.5: a few pulls of homemade maple and honey gel - Miles 5, 10, 15, 20, and 25: 2 to 3 pitted dates - Every fuel stop: a sip of the frozen electrolyte drink, plus water at stations Because my stomach has been trained just like my legs, race day feels familiar. ## Foods I Avoid Before a Marathon The final 48 hours are not the time to experiment. I avoid: - Fried foods - Heavy sauces - Large salads - High fiber meals - Excess cheese - Greasy takeout - Fatty meats like bacon and sausage - Pastries, croissants, and muffins - Seed oils - Alcohol - Anything I've never tested A healthy digestive system is every bit as important as healthy legs. ## Practice Everything One of the biggest mistakes runners make is treating nutrition differently than training. You wouldn't buy a brand new pair of shoes on race morning. Don't do it with food either. Every breakfast. Every gel. Every drink. Every electrolyte. Every snack. Practice all of it during long runs. Four to six long runs of 12 miles or more with your full fueling system is usually enough for your gut to adapt. At least twice before your target race, run the complete 48-hour carb load before an 18 to 20 miler as a full dress rehearsal. Your digestive system adapts just like your muscles do. ## Final Thoughts There are countless marathon nutrition plans. This one is mine. It was developed while balancing marathon training with a full-time career behind a desk. It's been refined over hundreds of training miles and helped me run a 3:25 marathon while continuing to chase a 3:10. Keep your nutrition simple. Use real, single ingredient foods, organic when you can, and skip the processed stuff. Practice your fueling until it becomes automatic. Train your stomach the same way you train your legs, and you'll give yourself the best chance to cross the finish line feeling strong. Fuel early. Fuel often. Never wait until you need it. --- Want the full system? Read my complete [Marathon Fueling Blueprint](/courses/how-to-run-marathon/diet-and-fueling) with the exact carb-load calendar and race-day plan.