What to Eat Before a Half Marathon

This guide explains what to eat and when, including how to fuel during the race, so you've got one less thing to worry about on race day. For advice on everyday fuelling, see our running nutrition guide.

Why fuelling for a half marathon matters

When you run, your body relies heavily on carbohydrates stored in your muscles and liver as glycogen. But those stores are limited, and after about an hour and a half of running, they’ll usually start to run low, resulting in a big performance drop-off.

That's why a half marathon requires a bit more thought than a 5k, although you won't necessarily need the same carb-loading approach as someone running a full marathon. Eating enough carbs beforehand and having a plan for fuelling during the race can help you avoid running out of energy in those crucial final miles.

Still working towards 13.1? Check out our half marathon training guide.

What to eat the week before a half marathon

No dramatic changes are needed in the week before your race. Keep it simple: eat balanced meals, ideally ones you know, and gradually increase the carbohydrates on your plate.

In the final 24-48 hours before the race, if you're expecting to be on the course for longer than 90 minutes, aim for 6-8 grams of carbs per kilogram of bodyweight each day. That's 420-560 g for someone weighing 70 kg, but don’t stress about getting this exactly right, especially if it’s your first half.

A typical day's food might look like this:

• Breakfast: Porridge with a banana and honey.
• Lunch: A jacket potato with tuna and a bit of mayonnaise.
  
• Dinner: Chicken with rice and cooked vegetables.
  
• Snacks: A bagel with jam, or other familiar carbohydrate-rich snacks between meals.

What to eat the day before a half marathon

Now is not the time to be adventurous with food. In fact, it’s the time to be as boring as possible. Eat something you’d normally eat that you're confident won’t upset your stomach, and make sure it includes plenty of carbs.

It might feel strange to have your biggest meal at lunchtime, but doing so can make a big difference in how you feel on race day. Eating a smaller dinner means you’ll have less to digest before bedtime and should arrive at the start feeling light and ready to go rather than bloated.

What to eat the night before a half marathon

If you've got an early start the following morning, aim to eat dinner around 6-7pm, or at a time that gives you a decent gap before bed.

Some pre-half marathon race dinner inspiration

• Spaghetti marinara sauce with chicken: This classic dish is a great option for runners. The spaghetti provides the necessary carbohydrates, while the chicken adds some protein to the mix. Plus, the marinara sauce is low in fat and easy on the stomach.
• Baked salmon with roasted sweet potato and vegetables: If you're looking for a meal that is both delicious and nutritious, this is the one for you. Salmon is a great source of protein and omega-3 fatty acids, while sweet potatoes provide a healthy dose of carbohydrates. Roasted vegetables add some fibre and much-needed flavour to the mix.
• Brown rice with stir-fried veg and tofu (or chicken): This vegetarian option is packed with nutrients and flavour. Brown rice is a great source of complex carbohydrates, while the stir-fry veg provides fibre and vitamins. Tofu (or chicken) adds some protein to the mix, making this a well-rounded meal.

Foods to avoid before a half marathon race

While it's important to focus on what to eat before a half marathon, it's equally important to know what to avoid. Certain foods can cause digestive problems like bloating and cramping, which can negatively impact your race.

Here are some foods to avoid to keep you in tip-top condition on race day:

• High-fat foods: Foods that are high in fat can take longer to digest, which can cause discomfort during the race. Avoid fast foods, fried foods, and fatty meats - a fry-up breakfast of champions might seem like a good idea, but really isn’t advisable!
• High-fibre foods: While fibre is important for overall health, it can cause digestive issues for some people. Avoid foods like beans, lentils, and broccoli, which are high in fibre if you’re in this camp.
  
• Spicy foods: Spicy foods can irritate the digestive system, causing discomfort and even diarrhoea - save the curry for the celebration afterwards!
  
• Alcohol: While it may be tempting to have a glass of wine or beer with dinner, alcohol can dehydrate you and negatively impact your performance. It's best to avoid alcohol before a race and instead think of it as your treat afterwards.

What to eat on the morning of a half marathon

The ideal time to eat breakfast is two to three hours before the race. That way, you’ll have plenty of time to digest the food before you arrive at the start line.

Try to eat around 1-2 grams of carbs per kilogram of body weight, or whatever worked well during your long training runs. Great pre-race breakfast options include:

• Porridge with banana and honey or jam
• A white bagel with honey and sliced banana (my favourite - I sprinkle cinnamon and nutmeg on top too) or jam
• Toast with jam and a glass of fruit juice
• Muesli or granola
• Pancakes with golden syrup

Stay hydrated by drinking a glass of water when you wake up and then sipping regularly throughout the morning. Don’t overdo it, though, because dashing to the portaloos when the race is about to start is never fun! Our running hydration guide covers what to drink before, during and after a race.

If coffee is a normal part of your routine, there’s no need to skip it. Caffeine can boost your performance, but it can also upset your stomach if you’re not used to it, so bear that in mind.

Planning your race morning

Work backwards from your start time and aim to finish breakfast 2-3 hours beforehand. Factor in how long it'll take you to travel to the event, drop off your bag and use the toilets, and check when your starting pen closes. If you’re travelling a long way for a race, I recommend bringing breakfast with you rather than getting up ridiculously early.

If your race starts at 9am

• 6:00am: Wake up and have breakfast by 6:15am.
• 7:00am: Leave for the race (take some water with you!).
• 8:00am: Arrive, drop off your bag and locate the toilets.
• 8:30am: Have a small snack if you've practised eating this close to a run.
• 8:40am: Warm-up and make your way to the start.
• 9:00am: Your race begins!

Fuelling during a half marathon: gels, drinks, and how much you’ll need

Consuming carbohydrates during a race helps you keep your energy levels up, especially if you’ll be running for longer than 90 minutes. A good rule of thumb is to have 30-60g of carbs per hour, which you can get from energy gels or sports drinks.

Since most gels contain around 20-25g of carbs, you’ll need to take one roughly every 30-45 minutes. Practise this in your training runs so you know what works for you!

How many gels do you need for a half marathon?

The number of gels you’ll need depends partly on your estimated finish time and partly on how you feel when you test out your fuelling strategy during training. Some people run better when they use more gels; others do better with less. That’s why the table below contains rough guidelines, not set rules.

What to eat after a half marathon

Once you’ve crossed the finish line and the adrenaline dies down, it’s time to think about food again. Eat something with both carbs and protein within the first hour after finishing to replenish depleted energy stores and support muscle repair.

Understandably, you might not feel like eating a proper meal at this stage, so here are some alternative options:

• A banana and a protein yoghurt or shake
• A chicken sandwich
• A smoothie with milk, banana and yoghurt

Don’t forget to drink plenty of water and continue eating balanced meals over the next few days to help your body recover.

If you’re still planning your next race, find a half marathon that gives you time to train and fuel properly.

Frequently asked questions

Should I carb load for a half marathon?

Increasing your carbohydrate intake in the final couple of days before a half marathon can help keep your energy up longer during the race, especially if you expect to run more than 90 minutes. You don't need to follow the same carb-loading protocol as someone running a full marathon, though.

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

Pre-race nerves make it difficult for some runners to eat. If that happens to you, try a smaller portion of easily digestible carbs, like white toast with jam, or a high-carb drink. Something is better than nothing.

Can I run a half marathon without energy gels?

You don’t have to use energy gels during a half marathon. Sports drinks and energy chews are perfectly good alternatives, and you could even try jelly babies if you have a sweet tooth. You can run a half without fuelling at all if you have well-trained glycogen stores, but most people will hit a wall if they try.

***

Related guides:

• Running nutrition guide
• Running hydration guide
• The ultimate race day checklist
• Half marathon training guide
• The best half marathons in the UK
• What is a good half marathon time?
• Half marathon kit list