Fueling Long Runs: What to Eat and Drink on the Road

Your muscles and liver store carbohydrate as glycogen — roughly 400 to 500 grams in a well-fed runner, equivalent to about 1,600 to 2,000 calories. At easy pace your body burns a mix of fat and carbohydrate, so glycogen lasts longer. As pace rises or the run extends beyond 90 minutes, you draw more heavily on those stores. When they run out, fat alone cannot fuel the intensity you need, and pace drops sharply.

The practical upshot: for any run lasting longer than 75 to 90 minutes, what you eat before and during the run matters as much as your fitness.

Eat a carbohydrate-centered meal two to three hours before your long run. Oatmeal with banana, toast with peanut butter and jam, or rice with a little protein all work well. Keep fat and fiber modest — both slow gastric emptying and can cause problems when your gut is being jostled at running pace.

If your schedule means you run early and can't eat a full meal, a small easily-digestible snack — half a banana, a gel, or a slice of toast — 30 to 45 minutes before you head out is far better than nothing. You're just trying to top off the overnight glycogen drop before a hard effort.

Start taking carbohydrate before you feel hungry or tired — roughly 45 to 60 minutes into the run. If you wait until you feel depleted, your glycogen is already low and restoring pace takes time. Early, consistent intake is far more effective than catching up.

Aim for 30 to 60 grams of carbohydrate per hour. More experienced runners with trained guts can push 60 to 90 grams per hour by combining glucose and fructose sources, which use different intestinal transporters and clear the gut faster. Start at the lower end and build up across several training runs.

Drink to thirst rather than on a rigid schedule — research consistently shows this matches intake to actual need better than prescribed volumes. Plain water is fine for runs under 60 to 75 minutes. On longer efforts, you also need sodium to replace what you lose in sweat. Without it, drinking large amounts of plain water can dilute blood sodium and cause hyponatremia — rare but serious.

A sports drink, electrolyte tab dissolved in water, or a salty snack alongside plain water all provide the sodium you need. How much you sweat varies enormously by individual, intensity, and temperature — if you finish long runs severely thirsty or with visible white salt marks on your kit, you probably need more.

After a depleting long run, eating carbohydrate and protein within 30 to 45 minutes helps kickstart glycogen replenishment and muscle repair. This recovery window matters most after long or high-intensity efforts when stores are significantly drawn down — it's less critical after an easy 45-minute jog.

You don't need a special product: chocolate milk, a bowl of rice with eggs, or yogurt with fruit all hit the right macros. What matters is eating something rather than skipping the meal and getting to it faster than you otherwise would.

Your gut is trainable. Taking carbohydrates while running can cause nausea at first, especially at intensity, but consistent practice in training desensitizes the stomach over several weeks. Use the long runs in your plan — whether that is Higdon Novice 1 building toward 20 miles, Pfitzinger 18/55 with its stacked midweek volume, or the Hansons cumulative-load approach — to rehearse your exact race-day nutrition.

Know the gels and drinks available on your race course and train with them specifically. Race day is never the time to discover your stomach disagrees with a new brand. Use the anystride pace calculator to lock in your goal pace before race week, then plan how many aid stations you will hit and whether to carry your own fuel or rely on the course. The combination of practiced nutrition and a smart first-mile pace is what keeps the wall from appearing at mile 20.