Knowing how to fuel, or what to eat before a half marathon is an essential part of your race day performance.
Your body can store energy in the form of glycogen in your muscles and liver, so ensuring you’ve got these reserves topped up means you’re more likely to do well in your half marathon!
Carb-loading (stocking up on carbohydrates in the days before a race) isn’t necessary for shorter race distances like 5k or 10k; but once you’re running for over 90 minutes, you need to start thinking about that fuel.
In this post, I’m going to break down what you should be eating…
- the week before your half marathon
- the day before your half marathon
- the night before your half marathon
- the morning of your half marathon
- during your half marathon
- and after your half marathon!
Many runners give themselves a huge disadvantage by training hard for several months, only to not fuel properly in the weeks, days, and hours before their big race..
I remember my first half marathon well; I didn’t modify my diet prior to the race, instead, I just relied on the sports drink given out at the aid stations.
And boy, did I feel it. I bonked – hitting the wall – around the 11 mile mark, and wanted to quit right there.
For my next half marathon, I actually prepared.
I did some research on what to eat before a half marathon and began eating pasta and loading up on carbs in the days leading up to the race.
On race day I had a big smoothie for breakfast, then I chugged a couple of sports gels on the route.
My formula wasn’t perfect, but … what a difference – I felt good for the entire 13.1 miles, and finished strong.
I was actually able to enjoy the race.
Since then, I’ve gone on to research race nutrition and work with nutritionists – and have captured the best practices in this article!
Ready to learn how to fuel before a half marathon?
Let’s jump in!
Table of Contents
The Role of Carbohydrates In Race Preparation
During exercise, our body pulls fuel from two macronutrient sources – carbohydrates and fat.
Typically, carbohydrates are more readily-available and quicker to convert to energy. Also the harder we’re exerting ourselves, the higher % of our energy comes from stored carbohydrates.
Carbs are stored in our muscles and liver before being converted to energy. Once those stores are completely depleted, the body is forced to turn to converting fat to supply all our energy needs.
This is often an inefficient process, and explains why so many runners ‘hit the wall’ or bonk – they’ve run out of readily-available carbs, and their bodies can’t convert fat to energy fast enough.
That’s why it’s important to both:
- ensure your carb reserves are fully-stocked before your race
- continuously top them up as you run.
Let’s look at how to do this effectively…
What To Eat The Week Before a Half Marathon
Your carbo-loading should begin around 3 days before your half marathon; this is enough time for you to properly fill up those reserve tanks to get you through your 13.1 miles.
As your half marathon approaches, you want to start to think about how you can be adding in extra carbs to your diet.
You can’t do all your carb-loading in a single sitting – it’s got to be spread out over a few days.
It’s recommended that you consume around 4 grams of carbs for every pound of body weight, each day. So if you’re a 150-pound runner, for example, you’d be aiming for 600 grams of carbohydrates every day.
But unless you’re willing to bust out a spreadsheet, you’re probably unlikely to track your exact carb consumption.
So what would this look like?
Here’s an example day:
- Breakfast of porridge oats with forest fruits and a glass of OJ, or a loaded breakfast smoothie.
- Mid-morning snack: bagel with salmon and cream cheese
- Lunch: Pasta with vegetables in a light dressing (minimal oil)
- Dinner: A sweet potato with guacamole and side salad.
You’ll notice that the portion sizes don’t necessarily increase; instead, we’re just focussing on increasing the ratio of carbs in your diet.
Likewise, the mid-morning snack might not be something you normally do – but it’s a great way to top up those carb levels without overeating.
Some more things to consider in the days leading up to your half marathon:
- Prioritise sleep. Your energy levels on a given day are related to your sleep quality over the past several days, so to ensure you’re well-rested on race day hit the hay early!
- Reduce or cut out caffeine. Related to sleep quality and energy levels, consider limiting your caffeine intake in the days leading up to your half marathon. As a minimum, cut out any post-lunch coffees. But feel free to take a coffee on race day, it can aid your performance!
What To Eat The Day Before a Half Marathon
If you’ve been carb-loading for a few days already, the day before your marathon should be no different.
Aim to have meals with high carbohydrate content such as pasta, rice, oatmeal, bread, yoghurt, and pancakes.
Just don’t overeat – the gastrointestinal stress it can cause won’t do you any favours.
Instead, stick to 4 reasonably-portioned meals per day (sneak in that mid-day snack).
Also, careful with your caffeine intake today; tonight you’ll likely have the pre-race jitters, no need to make them worse by adding some coffee brain to the mix!
Likewise, avoid alcohol completely today – it’s effects can have an impact on your half marathon performance. Save it for your post-race beer.
What To Eat The Night Before a Half Marathon
The pre-race evening meal is a key component in planning what to eat before a marathon.
By now, you should be well loaded with carbohydrates to fuel you through your 13.1 miles!
You still want to have a carb-rich meal, but on the night before your half marathon, you want to keep the portion size relatively small, and eat early.
This means you’ll digest the meal well and wake up slightly hungry; as opposed to over-eating and having your body process the food all night.
I normally opt for something like a medium-sized bowl of pasta with pesto and cheese. It’s something I know I can digest fairly easily and won’t sit in my stomach for hours on end.
Pasta parties used to be a thing the night before a race – the truth is that many runners simply ate too much pasta, overloading their body the night before their race.
Carb-loading needs to be spread out evenly over 3-4 days in order to fill those reserves in a sustainable way.
What To Eat The Morning Before a Half Marathon
You’ve made it to race day!
But wait – the carb-loading hasn’t quite finished yet!
You want to eat a light meal 3 hours before your half marathon begins, comprising of around 150 grams of carbs.
This might be some oatmeal with a nut butter mixed in, or a bagel and yoghurt.
If you have an early morning race, you still need to do this – set an alarm, eat breakfast, go and lie down again.
And at the start line? Another key point in what to eat before a half marathon.
You want to consume one more hit of carbs 30-45 minutes before the start time.
Keep this simple – stick to sports nutrition such as energy gels, sports drink, chews, or trail mix.
What To Eat During a Half Marathon
During your half marathon, your goal is to keep topping up your carb levels so they don’t bottom out – otherwise you’ll bonk, or hit the wall.
The best way to do this is with sports nutrition products such as energy gels, chews, and sports drinks – consume one every 30-45 minutes in order to add to those energy levels.
Remember it’s important that you don’t eat anything on race day that you haven’t trialed during training.
Everyone’s body reacts differently to sports nutrition, and some people simply can’t stomach gels so have to find an alternative product – like jelly beans or trail mix – that they can handle.
Good luck – and remember to keep topping up!
What To Eat After A Half Marathon
From the moment you cross the finish line, your body is actively seeking nutrition to kick-start the recovery process.
It may not be the first thing on your mind as you receive your medal, but you have a window of around 60 minutes in which to maximise your recovery by eating something.
Your muscles are primed to receive nutrients at this point – so consuming a mixture of carbohydrates and protein can really help kick-start the recovery process.
And while beer and burgers may be the obvious post-race meal option, remember to consume plenty of water and try to eat (relatively) healthily for a rapid recovery!
Looking for more guidance on what to eat before a half marathon?
Check out our meal plans- they’re free, and an INSTANT download!
Take Your Running Further With Our Resources...
Half Marathon Resources
Marathon Training Resources
Ultramarathon Training Resources