What To Eat Before A Half Marathon: The Ultimate Runner’s Guide!
Race day is coming up and you find yourself wondering what to eat before a half marathon? We all know that nutrition is important before a half marathon race, as with any long run, so it's important to get it right.
Maybe it's your first half marathon, maybe you're a pro, either way it's a good idea to brush up on some nutrition tips so you know you are eating the right foods in the run up to the race.
In this article, I will run through every stage of half marathon nutrition, from carb loading to step by step guides to what to eat the week before, day before, night before and morning of the race. As a bonus, I've even included what to eat during and after!
From my work as a sports nutritionist, these are the tips I would give to any of my personal clients - and they have helped so many runners hit their personal best goals!
Enjoy, and happy running!
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Carb Loading Before A Half Marathon: Why Are Carbs Important?
There's a lot of talk about carb loading in the running community; how to do it, whether it works, when is it most effective? Let me break it down for you.
Carb loading is an effective race nutrition strategy. There are many studies which suggest that carb loading before a race improves overall performance.
But what is the science behind carb loading? Your body has two main sources of energy; carbs and fat. Carbs are stored in your body as glycogen, primarily in your muscles and your liver. Your fat stores are essentially unlimited, however your carb stores are finite.
Most people have enough glycogen stores for around 90 minutes of hard exercise before they run out and their energy levels drop.
To make sure you have enough to get you across the finish line of your big race, you need to have as many carbs as possible stored in your body when you start the race.
That is why carb loading is important! Now I’ll talk you through the stages of half marathon nutrition, including carb loading and when to start/stop it.
What To Eat The Week Before A Half Marathon
It is not hard to plan what to eat a week out before a half marathon. This period is too early to start carb loading, so the best way to go is just to stick to your usual healthy training period diet.
This should have a good balance of whole grain carbs, healthy fats and lean protein.
In order to recover well, I would recommend eating around 1.4g to 2.0g of protein per kilo of bodyweight per day.
I would also recommend a small calorie surplus to give you enough energy for recovery from training sessions.
You might want to use this period to practice your pre-race meal, just to check that it doesn't have an adverse effect on your digestive system! If you would like gold star nutrition points, practise this meal a couple of times, weeks out from your race and run afterwards too. This will make doubly sure that you tolerate it well!
Around 72 hours before your half marathon, you can start transitioning to a lower fibre, high carb diet, to prepare your body for carb loading. In order to do this, you need to reduce the amount of vegetables, protein and complex carbohydrates, and transition to simple carbs.
Transitioning to a lower fibre diet can include choices like white bread instead of wholemeal bread
What To Eat 48 Hours Before A Half Marathon
I usually recommend starting to carb load about 36-48 hours out from your race start, because this is how long you need to properly maximise your carb stores and also give a little leeway to account for using them up during the day too.
To effectively carb load, you should be consuming 10 grams of carbs per kilo of body weight, at intervals throughout the day. Try to have larger meals earlier in the day and a light snack in the evening, because it's not fun to go to bed on a stomach full of carbs.
It is a good idea to consume some of these carbs in liquid form, such as an energy drink, sports drinks or juices - for the same reason that this amount of solid foods can be quite heavy!
Make sure you keep hydrated during this period. Your body will be processing a lot of simple sugars which get converted to glycogen, and as you store water with glycogen you will need plenty of water to balance this out.
Here are some carb loading meal ideas for inspiration:
Pasta with tomato sauce
Bagel with low fat cream cheese
Peanut butter sandwich (small amount of PB)
Oatmeal with berries
Jacket potato with tuna
Tuna pasta
Roasted Sweet potatoes
Granola and honey
The same applies to what to eat the day before a half marathon - it’s all about the carb loading!
In terms of what to do the day before a half marathon, you should have stopped any intense training by then, so just relax, sort your race kit out and mentally prepare for your race.
What To Eat The Night Before A Half Marathon
This marks the end of your carb loading period. You should wind down your carbohydrate intake over the day, so that in the evening you only need to eat a small meal that won't sit heavy on the stomach.
Many runners make the mistake of eating a huge bowl of pasta the night before a half marathon and wake up feeling groggy and full the next day, and don’t sleep well. Pasta is still fine, you just don’t need to go crazy. And as a snack after, you could always try a sandwich or a wrap instead.
If you've done the last 48 hours well, you will already have the majority of your carb energy stores in place ready for the big day!
What To Eat For Breakfast Before A Half Marathon
The day of the race has arrived! Time to think about what to eat before a half marathon in the morning.
Breakfast before a half marathon is both very important and not important at all!
Let me explain: what you eat for breakfast won't really affect your performance in terms of giving you more energy.
The 48 hour carb loading period is when the difference will be made in that area. Your breakfast is really just to top those stores back up and make you feel good - not overfull, but just enough to satisfy hunger.
It’s also important in terms of the risk of an upset stomach during the race. This will be the last meal you eat before you hit the starting line, so it is important to make good choices.
Stick to simple white carbs that are low in fibre. When I run, my go to is usually a simple breakfast of white toast and jam. Other ideas include oatmeal with honey, low fat rice pudding, or sweet banana bread. If you really struggle, you could opt for a liquid drink option like a sports drink. Lots of runners use Maurten - check out my unsponsored Maurten review here.
This might be a good time to mention foods to avoid before a half marathon!
High fibre foods take a long time to digest, so are likely to still be in your body when you start running if you eat them before a race. So avoid anything high fibre.
Pulses are a high fibre food you will want to stay well clear of - no one wants to run a marathon with the most notoriously flatulence-inducing food in their stomach!
The same applies to protein sources like eggs. Even though these are usually a healthy option, protein takes a long time to break down so lots of protein is not a good choice for a pre-race breakfast.
You will also want to steer clear of anything remotely greasy or fried, as the main component of this will be fat - which is also hard to digest and make you feel sluggish and heavy.
Of course, everyone's body is different, so these guidelines are just a general rule of thumb! You need to find out what works for you. The most important thing really is not to eat any new foods on the day of the race and practise well in advance.
Practise your breakfast in the days and weeks preceding your race, so you know it doesn't cause GI distress. That way you can be certain you are not running any risks come race day!
Should You Use Caffeine For A Half Marathon?
Lots of people ask me about this. Did you know caffeine is one of the only supplements that is actually proven to benefit your performance when running long distances? It has been shown to improve alertness, focus and reduce perception of effort.
The recommended dose of caffeine is 1-3mg of caffeine per kg of body weight. The half life of caffeine is 6-8 hours, which means anything you consume in the hour or two before your race should still be having a full effect by the time you finish.
If you are used to drinking caffeine, then stick to your routine and have that cup of joe in the morning. If you’re meticulous about how much caffeine, then you can use sport specific caffeine products to ensure you’re getting your perfect dose.
However, I would be wary of consuming caffeine on race day if you don’t usually, or if you haven’t practised it during training. It may have performance benefits, but it also has well documented laxative effects....
A common runners’ choice for breakfast - White bagel with jam and a banana
What To Eat During A Half Marathon
During the race, you will want some quick releasing energy bursts at regular intervals - this should be consumed as carbohydrates
A great way to achieve this is by consuming energy gels throughout the race. These are lightweight, easy to digest and packed full of carbs. You can easily store them on a running belt like this one and consume them on the go.
You should be aiming to consume around 50g carbs an hour as a starting point - but you can trial this in training and see whether you need more or less than that.
If you decide to up the distance, I have a guide to using Maurten gels and drink mixes to fuel a marathon!
I wouldn't recommend eating energy bars, or any solid foods while running a half marathon. They are heavier, harder to eat on the go and will take a long time to break down in your stomach so you increase the risk of gastro upset.
And of course, consider hydration. A half marathon is short enough to not require any aggressive rehydration strategy. If you feel thirsty - drink. If you don't, then don't force it.
You can pick up water along the way at aid stations, or carry your own pouch on your running belt.
What To Eat After A Half Marathon
Once you finish your race, your body will need and be in the perfect state for receiving protein, carbs and electrolytes. However, you may be a little bit sensitive after so much exertion, so I generally advise against going for a big meal straightaway.
A good option here would be something like a smoothie or milkshake. If you want to eat something, go for cereal bars or other small, nutritious snacks. I love a big protein smoothie with oats, protein powder, honey and a banana.
For the 24 hours after your race, keep going with the carbs as this will help to restore your body's glycogen levels. After that period is over and you have recovered, you can start returning to your normal diet, with plenty of protein, healthy fats and fibre.
Hydration is now also a super important part of recovery. I recommend drinking 500ml of fluid every hour for a minimum of 2 hours after finishing your race.
If you ran in hot conditions, add some electrolyte tablets to your water, so you can fully rehydrate and replenish your sodium levels. I recommend 250 mg of sodium per 500ml of fluid, or 500mg of sodium per 1 litre of fluid.
That's all from me on what to eat before a half marathon! Check out my carb loading meal plan for a pre-race nutrition plan that will prepare you perfectly for the big day!
