What to eat before a half marathon (and the night before)

What to eat before a half marathon, in one line: a carb-forward dinner you've eaten before the night before, then a familiar carb breakfast two to three hours before the start, low in fat and fiber. Nothing new. Nothing heroic. It's your long-run routine with a race number on.

The rest is detail: how much, how early, what the night before looks like, whether carb loading is worth it for a half, and what to do if your start time makes breakfast awkward. If you'd rather have the training and the timing worked out for you, an app that programs strength and running for you handles the build. Breakfast is still yours.

One note up front: this is general practice, not a personal prescription. If you have diabetes, a GI condition, a history of disordered eating or anything else clinical, talk to a doctor or a registered dietitian before changing how you fuel.

What to eat before a half marathon: the short version

• ›Carbohydrate is the main event. Oats, bagels, white toast with honey or jam, rice, bananas, plain cereal.
• ›Keep fat, fiber and protein modest. Not zero. Just not the diner breakfast platter.
• ›Eat what you've eaten before long runs. Race day is the performance, not the audition.
• ›Drink some water. Enough that you're not starting dry, not so much that you spend the first mile looking for a toilet.

Why low fat and fiber? The joint position stand from the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine says foods low in fat and fiber, with low-to-moderate protein, are the preferred pre-event choice because they're less likely to cause gastrointestinal problems (Thomas, Erdman and Burke, 2016).

If you're following a 12-week half marathon plan, your long runs are where you test all of this. And if this is the first time you've thought about pre-run food, start with what to eat before a long run. Race day uses the same rules.

How long before a half marathon should you eat?

The position stand's pre-event guideline for exercise longer than 60 minutes is 1 to 4 g of carbohydrate per kilogram of body weight, eaten 1 to 4 hours before (Thomas, Erdman and Burke, 2016). It also says the timing, amount and choice should suit the individual. Which means: test it.

The closer to the start, the smaller and simpler the food:

Here's what the 1–4 g/kg range works out to by body weight. It's just multiplication, so do it for your own number:

The top of the range is a lot of food. Most people only get near it with three or four hours to digest. On race morning, two to three hours before the gun is a comfortable window for most runners. Count back from your start time, not your alarm, and remember the travel, the bag drop and the toilet queue.

What to eat the night before a half marathon

Less drama than people think. The night before a half marathon is dinner, not a ceremony.

• ›Make it carb-forward. Pasta, rice, potatoes, noodles, bread. A normal portion, maybe a little more.
• ›Keep it familiar. The night before the race is not the night to try the new spicy place.
• ›Go easy on fat, fiber and alcohol. You don't need to be strict. You need to not be sprinting to a portable toilet at mile six.
• ›Eat at a normal time. A huge, late dinner turns race morning into a digestion test.

If you're traveling, book a restaurant that serves something boring, or bring your own.

What to eat the night before a 10K run follows the same rules with lower stakes, because a 10K is short enough that dinner matters less. For the half, it's worth getting right.

Should you carb load before a half marathon?

Maybe. It depends on how long you'll be running.

The position stand's carb-loading guideline is 10 to 12 g of carbohydrate per kilogram per day for 36 to 48 hours, for events longer than 90 minutes of sustained exercise (Thomas, Erdman and Burke, 2016). For shorter events, it lists 7 to 12 g/kg per day, the same as normal daily fuel needs.

So:

• ›Finishing in under about 90 minutes? Eat your normal carb-heavy diet in the days before. A formal load isn't what the guideline is for.
• ›Finishing beyond 90 minutes, which is most half marathoners? A carb load over the last day or two may be worth it. 10 to 12 g/kg is a lot of food, so most people lean on low-fiber carbs like rice, white bread, juice and sweets rather than a mountain of whole grains.

Either way, carb loading before half marathon explained comes down to more carbs in the last couple of days, less fiber, and nothing your stomach hasn't met before. If you've never tried it, try it before a long run first.

Race-morning breakfast ideas

Pick one you've used before at least a few long runs:

• ›Oats with banana and honey
• ›A bagel or two with jam
• ›White toast with honey and a banana
• ›Rice with a little salt
• ›Plain cereal with milk, if dairy sits well with you
• ›A sports drink or juice if you can't face solid food

Coffee is fine if you normally drink it. Race morning is not the day to start.

The days before: training, rest and lifting

Food is only half of race-week prep. The other half is not wrecking your legs. If you've followed a half marathon build that keeps your lifting, your last heavy lower-body session should be a week or more behind you. The day before the race should be easy or off, and a guide to rest days has ideas for what that can look like, beyond lying on the sofa refreshing the weather forecast.

The same logic scales up. If a full marathon is next, how to train to run a marathon explained uses the same fueling rules with bigger numbers and more practice.

During and after the race

What you eat before the half sets you up. What you take during keeps you going. For races over about an hour, the position stand's target is 30 to 60 g of carbohydrate per hour for efforts of 1 to 2.5 hours, and up to 90 g per hour beyond about 2.5 to 3 hours (Thomas, Erdman and Burke, 2016). Burke et al., 2011 give the same ranges. Our guide to half marathon fueling turns that into gel counts and timing.

Afterwards, eat something with carbs and protein once your stomach settles, and drink. What to eat after marathon day, or half marathon day, is mostly normal food in decent amounts.

Common mistakes

• ›A new breakfast on race morning. The long runs were the rehearsal. Use them.
• ›A giant, fiber-heavy "healthy" breakfast. Great on a rest day. Less great at mile eight.
• ›Eating too close to the start. Big breakfast, 45 minutes before the gun, plus nerves. Bad combination.
• ›Skipping breakfast because of nerves. If you can't eat, drink something with carbs.
• ›Treating carb loading as an all-you-can-eat event. More carbs, not more of everything.

How exrsz handles this

exrsz builds a periodized half marathon plan from your goal, your schedule, your level and your equipment, with running and lifting in one plan, so race week isn't wrecked by a leg day you forgot about. It adapts each week to how you trained and reshuffles missed sessions. The bagel is your call.

FAQ

What should I eat before a half marathon?

A familiar, carb-heavy, low-fat, low-fiber breakfast two to three hours before the start, like oats, a bagel with jam or toast with honey and a banana. Use the same breakfast you've tested before long runs.

What should I eat the night before a half marathon?

A normal, carb-forward dinner you've eaten before, like pasta, rice or potatoes, at a normal time. Go easy on fat, fiber and alcohol.

How long before a half marathon should I eat?

The ACSM, Academy of Nutrition and Dietetics and Dietitians of Canada position stand gives 1 to 4 g of carbohydrate per kg, 1 to 4 hours before exercise longer than an hour (Thomas, Erdman and Burke, 2016). Most runners eat two to three hours before the start.

Do I need to carb load for a half marathon?

Only if you'll be running longer than about 90 minutes. The position stand's carb-loading guideline of 10 to 12 g per kg per day for 36 to 48 hours applies to events longer than 90 minutes (Thomas, Erdman and Burke, 2016).

What if I'm too nervous to eat before a half marathon?

Try something small and simple, like a banana or a sports drink. Practice your race-morning routine before long runs so it feels normal on the day.