What to eat before a long run (and the night before)

What to eat before a long run, in one line: a carb-heavy meal or snack you've eaten before, low in fat and fiber, one to four hours before you start, sized to how much time you've got. The night before, eat a normal dinner that leans on carbs. Don't invent anything new on the day of the run.

That's genuinely most of it. The rest is the detail: how much, how long before a run you should eat, what the night before looks like, what to take during, and how the gym fits in. It's the kind of thing you'd want a coach that adapts when life gets in the way to handle, because the right answer moves with your schedule.

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 long run: the short version

• ›Carbohydrate is the main event. Rice, oats, bread, bagels, potatoes, pasta, bananas, cereal, white toast with honey or jam.
• ›Keep fat, fiber and protein modest. Not zero. Just not a full English breakfast.
• ›Eat what you've eaten before. The long run is the dress rehearsal. Your stomach should know the script.
• ›Drink some water too. Not a gallon. Enough that you're not starting dry.

Why the 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 with low fat, low fiber and low-to-moderate protein are the preferred pre-event choice because they're less prone to causing gastrointestinal problems (Thomas, Erdman and Burke, 2016). Translation: the lentil salad can wait until after.

The long run is usually the session most worth fueling properly, because it's the longest and most demanding run of the week. That holds whether you're following a half marathon schedule with strength or something shorter. In a 5K build, most sessions are short enough that fueling barely needs a plan, and there's more on 5k training for the running side of that.

How long before a run should I eat?

The position stand's pre-event guideline for exercise longer than 60 minutes is 1 to 4 grams 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 food choices should suit the individual, which is the polite way of saying you have to test it.

The common-sense way most runners apply that range: the closer to the run, the smaller and simpler the food.

Here's what the 1–4 g/kg range works out to by body weight. This is 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. With an hour, the bottom end is plenty.

So, how long should I eat before a run? If you have the morning, two to three hours is a comfortable window for most people. If you don't, eat less, eat simpler, and eat closer.

What to eat the night before a long run

Less than people think. The night before a long training run isn't a carb-loading ritual. It's dinner.

• ›Make it carb-forward. Pasta, rice, potatoes, noodles, bread. A normal portion, maybe a little more.
• ›Keep it familiar. Not the spicy place you've been meaning to try.
• ›Go easy on fat, fiber and alcohol. You don't need to be strict. You need to not be running to a bathroom at mile eight.
• ›Eat at a normal time. A late, huge dinner turns a 7am run into a digestion test.

Race nights follow the same rules with higher stakes, which is why what to eat the night before a race is mostly about doing the same thing you've done before every long run.

Breakfast before a morning long run

Most long runs happen early, which squeezes the window. Options, from most time to least:

• ›Up two to three hours early (the race-day rehearsal): oats with banana and honey, bagels with jam, rice.
• ›Up 60–90 minutes early: toast with honey, a banana, a sports drink.
• ›Out the door in 20 minutes: a banana or a gel, plus water, and carbs during the run.

Some people run short easy sessions fasted and feel fine. A long run is a different animal: it's longer, and it's where you should rehearse race-day fueling. For shorter early sessions, what to eat before a morning run has a shorter answer: something small, simple and familiar, or a sports drink if you can't face food.

Drink before you go

The position stand suggests athletes can get adequately hydrated before exercise by drinking 5 to 10 mL per kilogram of body weight in the 2 to 4 hours beforehand, aiming for pale yellow urine and leaving time to go to the bathroom (Thomas, Erdman and Burke, 2016). For a 70 kg runner, that's 350 to 700 mL. Not a liter chugged on the start line.

What to eat during a long run

If the long run is over an hour, what you take during matters as much as what you ate before.

Two sources, same numbers:

• ›For sustained exercise lasting 1 to 2.5 hours, the joint position stand gives a target of 30 to 60 g of carbohydrate per hour, and up to 90 g per hour beyond about 2.5 to 3 hours (Thomas, Erdman and Burke, 2016).
• ›Burke et al., 2011 describe 30 to 60 g per hour as appropriate for longer events, and note that events over 2.5 hours may benefit from up to 90 g per hour, using products that blend different carbohydrate types to absorb more.

The high end is something you train up to, not something you try on race day. Start at the bottom of the range on long runs, see how your stomach handles it, and build. Energy gels for marathon training are the easiest way to hit those numbers, as long as you practise taking them while running.

What to eat before a long run, by race goal

The pre-run meal doesn't change much by distance. What changes is how long you'll be out there and how much you'll need during.

5K training

Long runs in a 5K build tend to stay short, often under an hour, so a light snack beforehand is usually plenty. Race morning is its own small question, and what to eat before running a 5K mostly comes down to eating early and eating little.

Half marathon training

Long runs in a half build often stretch past 90 minutes. That's where the pre-run meal and carbs during start to matter. If you're following a half marathon build that keeps your lifting, the long run is also the session that collides with leg day most often. Race morning follows the same playbook: what to eat before a half marathon is your long-run breakfast, eaten a little earlier.

Marathon training

Long runs in a marathon build get long enough that fueling is a skill you practise, not a meal you eat. Learning how to train to run a marathon includes learning how to eat on the move. If you're still deciding when to start, a guide to how long to train for a marathon helps you count back from race day.

Carb loading: only for the big ones

Carb loading is for race week, not every Saturday. 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 whether carb loading before a half marathon is worth it depends mostly on whether you'll be out there longer than 90 minutes.

Lifting the day before a long run

If you also lift, the long run and leg day are the scheduling conflict that refuses to die. A heavy lower-body session the day before your long run leaves you starting it tired, no matter how perfect breakfast was.

The fix is scheduling, not food: put heavy lower-body work earlier in the week, keep the day before the long run easy or off, and treat the long run as one of the hard days of the week. Rest days explained covers what the day before can look like when it isn't a training day.

From a fueling angle, a lifting day still burns through carbohydrate. If you trained hard the day before, don't skip dinner carbs out of habit.

After the long run

The long run doesn't end when you stop your watch. Eat something with carbohydrate and protein reasonably soon, especially if you've got another session in the next day or two. A 5K needs less refueling than a long run, but what to eat after a 5K follows the same idea on a smaller scale. Race day is the big one, and what to eat after a marathon comes down to carbs, protein and fluids once your stomach agrees to them.

Across a whole training block, your daily carbohydrate needs go up with your training load. The position stand lists 5 to 7 g/kg per day for a moderate program of around an hour a day, and 6 to 10 g/kg per day for endurance programs of 1 to 3 hours a day (Thomas, Erdman and Burke, 2016). That's the big-picture side of fueling: healthy eating for marathon training is mostly about eating enough, especially on your biggest training days.

Common mistakes

• ›Running a long run on coffee alone. Fine for 30 easy minutes. A two-hour run is a fuel problem with a schedule.
• ›Testing new food on race morning. The long run exists so race morning holds no surprises.
• ›Eating a huge fiber-heavy "healthy" breakfast. Great on a rest day. Less great at mile nine.
• ›Skipping carbs during long runs because "it's only training". The long run is exactly where you train your gut.
• ›Copying someone else's exact numbers. Bodies and stomachs differ. Use the ranges and adjust.

How exrsz handles long runs

exrsz builds a periodized plan from your goal, your schedule, your level and your equipment, with running and lifting balanced in one plan, so the long run doesn't land the day after heavy legs. It adapts each week to how you trained and reshuffles missed sessions. The breakfast is still on you.

FAQ

What should I eat before a long run in the morning?

Something carb-based, familiar and low in fat and fiber: oats, toast with honey or jam, a bagel, a banana. The less time you have before the run, the smaller and simpler it should be.

How long before a run should I eat?

The joint 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. Most runners eat a meal two to three hours before, or a small snack about an hour before.

What should I eat the night before a long run?

A normal, carb-forward dinner you've eaten before, like pasta, rice or potatoes, at a normal time. Ease off on fat, fiber and alcohol, and save carb loading for race week before events longer than 90 minutes.

Do I need to eat during a long run?

For runs longer than about an hour, carbohydrate during the run helps. Published guidelines target 30 to 60 g per hour for sessions of 1 to 2.5 hours, and up to 90 g per hour for longer, which you should build up to gradually in training.

Can I run a long run on an empty stomach?

Some people do, but a long run is where you should rehearse race-day fueling, so most runners eat something first. If you have a medical condition that affects blood sugar, talk to a doctor before running fasted.