If you’re training for a half marathon, marathon, or any race that involves long runs, what you eat beforehand can make a huge difference. Fueling properly before heading out helps you maintain energy levels, avoid mid-run fatigue, and reduce the risk of stomach issues.
Long runs are also the perfect opportunity to practice your race-day nutrition strategy. Testing different foods during training helps you figure out what works best for your body, so there are no surprises on race day.
In this guide, we’ll cover why pre-run nutrition matters, how much you should eat, and the best foods to choose before a long run.
Why eating before a long run matters
Eating before a long run serves two main purposes: it tops up your energy stores and helps your body handle fuel during exercise.
After a night of sleep, your blood sugar levels are naturally lower because you haven’t eaten for several hours. A small meal or snack before your run helps replenish those levels and provides your muscles with easily available energy.
There’s another important benefit too. When you eat before running, your digestive system is already active. This can actually make it easier to tolerate fuel later in the run, such as gels or sports drinks.
Without any food in your stomach, your body may divert blood flow away from the digestive system more quickly once you start exercising, which can make it harder to digest fuel during the run.
When should you eat before a long run?
Most runners benefit from eating one to two hours before starting a long run.
This timing gives your body enough time to digest the food while still providing energy for the workout. If you’re running early in the morning and don’t have much time, a smaller snack 30–60 minutes beforehand can still help.
The key is to experiment during training so you find a routine that feels comfortable.
How much should you eat?
For most runners, a pre-run meal should provide around 200–300 calories, primarily from carbohydrates.
Carbohydrates are the body’s main fuel source during endurance exercise, so they should make up the majority of your pre-run meal.
For longer runs lasting over an hour, sports dietitians often recommend aiming for roughly:
1–4 grams of carbohydrates per kilogram of body weight
If you’re new to eating before running, start with the lower end of that range and gradually increase as your body adapts.
Many runners also benefit from including a small amount of protein alongside carbohydrates. A common guideline is roughly a 3:1 ratio of carbs to protein.
The best foods to eat before a long run
The best pre-run foods are easy to digest, high in carbohydrates, and low in fat and fiber. Foods that are heavy, greasy, or very high in fiber can take longer to digest and may cause stomach discomfort during your run.
Here are some simple options that work well for many runners:
- Toast with nut butter and a banana
- Oatmeal with banana and maple syrup
- Graham crackers and a banana
- A bagel with peanut butter or honey
- Breakfast cereal with milk or plant-based milk
- Pop-Tarts or similar simple carbohydrate snacks
If you’re short on time, quick options like an energy gel and sports drink can provide fast-digesting carbohydrates shortly before your run.
The most important rule is to practice your fueling strategy during training rather than trying something new on race day.
What foods should you avoid?
Certain foods are more likely to cause digestive problems during a long run.
Try to avoid:
- High-fat foods
- Fried or greasy meals
- High-fiber vegetables like broccoli or cauliflower
- Large amounts of dairy (if you’re sensitive)
- Very spicy foods
Everyone’s digestive system is different, so it’s worth experimenting to see what works best for you.
Don’t forget hydration
Hydration is just as important as food before a long run.
A good general guideline is to drink 8–12 ounces (240–350 ml) of fluid about 30–60 minutes before running.
Sip gradually rather than drinking a large amount all at once. Drinking too quickly can cause uncomfortable stomach sloshing once you start running.
For longer runs or hot conditions, adding electrolytes to your drink may also help improve hydration.
What to eat during a long run
For runs lasting longer than about an hour, you’ll also need to take in fuel during the run itself.
Many runners aim to consume roughly 30–60 grams of carbohydrates per hour, often through energy gels, sports drinks, or chews.
A common strategy is to take small amounts of fuel every 20–30 minutes after the first half hour of running.
Again, long training runs are the perfect time to practice this strategy.
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