After months of logging long runs and gut-busting speed sessions, marathon week is finally here. You know you’ve got to fuel up to finish strong—but it's understandable if you're not sure exactly what to eat before a marathon.

The truth is, pre-marathon nutrition can be a little tricky. For example, you might have heard you should be carb loading—but when do you start, and for how long? Are some carbs better than others during this time period? Should you have a bagel or pasta for every single meal?

What you choose to eat (or temporarily avoid eating) in the days and hours leading up to your race has the power to make or break your marathon performance. The right balance and amount of nutrients can keep you out of the porta-potty, ensure you don’t bonk on the course, and even speed your recovery afterward. Below, learn everything you need to know about what to eat before running a marathon to set yourself for the best race possible.

Why Pre-Marathon Nutrition Is Important to Consider

It’s no surprise that endurance running can take a toll on your body. A marathon will use up your fluids, electrolytes, and stored energy (glycogen), plus break down muscle tissue. 

You may have even noticed this on your long training runs: If you don’t eat enough beforehand and fuel on the go, inevitably, you’ll begin to feel tired and start to slow down as the miles add up. 

Ironically, this can actually be helpful to experience early on. Training is the perfect time to practice your pre-marathon nutrition strategy and experiment with how different foods affect your running performance. For example, you might learn that you personally need to eat three hours before lacing up in order to run comfortably, even though your training buddy only needs one hour. Use each long run as a rehearsal so that, come race day, you don’t have any surprises. 

What to Eat During the Days Before a Marathon

Ultimately, you will want to have consumed enough carbohydrates to ensure your glycogen stores are topped off and ready for the race. This is where carb loading comes in. By upping the percentage of carbs in your diet, you’ll be able to stave off fatigue and maintain your pace for longer.

What does this look like? For three days before your marathon, you’ll generally want to bump up your carb intake to about 70–80 percent of your total calories at all your meals and snacks (while still taking in a bit of protein). While pasta and bagels are great options, other excellent choices include peeled potatoes and sweet potatoes, brown or white rice, smoothies, corn, applesauce, pretzels, and quinoa.

On the flip side, experts generally recommend limiting fat and fiber during this time, which can lead to gastrointestinal (GI) problems like bloating or diarrhea on race day. That means skipping things like croissants and doughnuts, as well as beans and cruciferous veggies, even though some of those are high in carbs. And stick to familiar options that you know your stomach can tolerate.  

Hydration is also important, especially on the final day before the race (particularly because your body needs extra water to store all that glycogen). You’ll know you’re drinking enough if you never feel thirsty and your urine has just a light yellow hue. You’ll also probably want to add in some electrolytes with a sports drink or electrolyte packet to help your body absorb and hold onto those fluids. 

What to Eat the Evening Before a Marathon

When you have less than 24 hours to go, you’ll want to choose your food wisely. 

The night before the marathon, continue to focus on carbs to increase your glycogen stores, but don’t try to overload—eating too much may leave you uncomfortable and bloated. (This is part of the reason why it’s smart to spread out your carb load over a few days.) Now is the time to really avoid fat and fiber, and zero in on simple carbs—think: white rice, bread, pasta, or potatoes with a little chicken, white fish, or tofu to help keep you satiated. 

Also, try to eat dinner early enough to give your body time to digest and store the energy you’ve just consumed.

What to Eat the Morning of Your Marathon

Get up and have breakfast early enough—ideally, three to four hours before you start the race—so your body will have time to digest what you eat. Stick with the same easy-on-the-stomach carbs (plus a bit of protein) that you’d normally eat before a long run. For example, your pre-marathon meal might look like instant oatmeal and a hard-boiled egg, a bagel with peanut butter and honey, or an English muffin with jam and juice. You might also make a smoothie with yogurt and a banana. 

Then, just before making your way to the starting line, you can top off your carb stores with a ripe banana, some candy, or an energy gel.

Of course, make sure you’re continuing to hydrate: There’s no need to chug, but you should slowly drink about 0.1 ounces of fluids for every pound of body weight (or 5–7 milliliters per kilogram of body weight) starting at least four hours before the race, according to the American College of Sports Medicine. For example, a 150-pound runner would want to drink about 15 total ounces in those hours before the race. This can come from plain water, an electrolyte drink, and even coffee (as long as you know your body can handle caffeine).

What to Eat During the Marathon

Marathon nutrition doesn’t end when you cross the start line. Refueling during the race gives your muscles the nutrients they need to keep up the pace and avoid hitting the dreaded “wall.”

Sports dietitians broadly recommend taking in anywhere from 30–90 grams of carbs per hour, based on the intensity of your race pace, weight, and other variables. Just know that you may need to train your stomach to digest those higher amounts while running (without getting nauseated or gassy), so this is something you’ll want to practice on your weekly long runs. You can get these carbs through energy gels, sports drinks, bananas, raisins or even candy.  

Remember: It will take your body a little time to access the carbs from mid-race snacks, so you’ll want to eat them regularly rather than waiting until fatigue sets in. Experts typically recommend having something every 30–45 minutes.

What to Eat for Your Post-Marathon Meal

Congratulations, you just ran a marathon! Now, it’s time to refuel. Within half an hour of crossing the finish line, you’ll want to eat about 20 grams of protein and 80 grams of carbs. This will help restock your glycogen levels and jumpstart your muscle repair and recovery. If you don’t have an appetite for solid foods just yet, try drinking some chocolate milk or a smoothie.

Once you sit down for a full recovery meal, choose foods that are high in carbs and protein, as well as antioxidants and omega-3 fats. Some dietitian-recommended ideas include pasta with chicken and veggies, a turkey avocado sandwich and fruit, or a baked potato with steak and veggies. Meanwhile, keep drinking ample fluids, including electrolytes. 

But remember that this is a celebratory meal—you just finished running 26.2 miles! If pizza or a burger is calling your name, go for it—just try to also get in those essential nutrients you need to recover. It can take up to 48 hours before your body is able to replenish the glycogen that was used up during the race, so don’t ignore your hunger cues following the race. 

What Not to Eat Before a Marathon

While all foods can have a place in a balanced diet, there are a handful of foods and beverages experts generally recommend avoiding shortly before a marathon so you set yourself up for race-day success. Here are a few things to keep in mind: 

Every single body is different, so it’s best to have a clear understanding of the effects different foods have on your body by testing out various meals and snacks during training. 

Common Marathon Nutrition Mistakes

If you’re training for a marathon, here are a few nutritional mistakes to avoid:

More Pre-Marathon Nutrition Tips

Here are some final tips when it comes to properly fueling your body for a marathon:

It’s worth reiterating that every runner is different and may have unique fueling preferences or health conditions to consider. If you have questions or need unique guidance for what to eat before a marathon, reach out to a registered dietitian or your doctor for more information.