What to eat before a 10k
Finding a balance between energy sustaining foods and foods that are easy to digest is the key for runners. The ideal pre-run meal or snack should be composed primarily of:
- Low GI foods
- Healthy carbohydrates
- Healthy fats.
Here I explain why these foods are so important before a run, plus I look at when you should eat them to achieve the best performance possible.
1. Eat - Low GI foods
The glycaemic index (GI) is a rating system for foods containing carbohydrates. It measures how quickly these foods are digested and how soon they affect blood sugar (glucose) levels after being eaten. The faster the body breaks these down, and blood glucose rises, the higher the GI rating.
For runners, it's important to eat foods containing low GI carbs, as these foods release energy slower and at a more sustained rate. This will help to preserve energy stores in the muscles and should allow fat sources to be used, thus ensuring energy levels are higher for longer.
It is particularly important to avoid ALL high GI foods in the 20 minute window prior to exercise as in this window there can be a physiological effect attached to the drop in blood glucose.
Low GI foods:
- Dried apricots
Look at our recipe hub to find inspiration for your pre-run meal – our spiced porridge is tasty and filling!
2. Eat - healthy carbohydrates
When it comes to carbohydrates, it is important not to overload as this group of foods can leave you feeling sluggish and bloated. However, if you are able to get the balance right, a small amount of carbs should help to see you through a run. That's because carbs are able to boost stores of glycogen which serves as a source of energy.
Healthy carbohydrate foods:
- Whole wheat pasta
- Brown rice
- Wholegrain bread
3. Eat - protein
A little bit of protein before a race can help you feel full for a longer period of time. On top of this, protein is really important for the muscles as it is used to build and repair tissue there. It makes up tendons, for example, as well as ligaments, collagen and elastin, the latter of which is essential for repair work. This means it is important to get protein both before and after a run.
Read our blog 'How much protein do you really need?' for further information on protein.
4. Eat - healthy fats
There are a number of reasons to consume healthy fats before a run. They provide fuel to sustain the body through a long distance, for example, and usually contain multiple nutrients too.
Increasing your intake of fresh foods and reducing your consumption of processed foods should help you to consume more health fats.
Foods containing healthy fats:
You could try our recipe for cranberry granola bars if you're after a delicious and healthy pre-run snack.
Foods to avoid before a run
As well as choosing certain foods to eat before a run, there are actually a few things that should be avoided as well. This should help to maximise performance and aid recovery in the days after a run! Read on to find out what you should not be eating.
1. Avoid - Fibre
A lot of the low GI foods can also be quite high in fibre. It is necessary to find a balance between low GI foods and a low fibre content as fibrous food can be hard to digest. This means they can cause frequent visits to the bathroom before or even during a long run – this is particularly true on race mornings when nerves are running high and digestion is less efficient.
By all means, include fibrous foods in your diet but keep quantities small and balance them with low GI foods which have lower fibre content. This will be a learning process over time – you may need to begin reading labels and eat fibrous food in a process of 'trial and error' to see if they make you feel fuller and more bloated.
The closer to your run, the less fibre you should eat. Four hours before running, for example, a larger meal containing more fibre can be consumed; however, thirty minutes before your run, you should avoid fibre altogether.
High fibre foods:
2. Avoid - High fat foods
Foods high in fat are also ones to avoid before a big run as these can only be digested slowly. This can make your stomach feel weighed down and may leave you feeling tired and low in energy.
High fat foods:
Try some of our healthy snacks as an alternative to chocolate and cake. Our peanut butter bliss balls are the perfect option!
3. Avoid - Caffeine
Caffeine is known to give you an energy boost so it can be tempting to have a coffee before a run. This is not a good idea, however, as caffeine can cause stomach upset and diarrhoea - not something you want to have to deal with while you are out on a run, especially if there are no restrooms nearby!
Sources of caffeine:
- Tea (including green tea)
- Energy drinks
4. Avoid - Sugar
Although sugar will initially provide a bit of an energy boost (or a sugar rush!), this isn't long-lasting and the inevitable crash in energy levels will soon follow. This means it is best to avoid sugary foods in the lead up to a run.
We know that sugars are abundant in the likes of cake and sweets, but don't forget they can be hidden in other, more surprising, sources too.
Unexpected sources of sugar:
- Fruit juice
- Canned soup
When to eat before a 10k
A big meal can often make us feel tired and weighed down which is not what we want right before a run. To prevent this, there are some general guidelines you can follow to ensure your food is properly digested before putting on your running shoes:
- 150-200 calories should be consumed every hour before a run
- If you consume a large meal, wait 2-4 hours before running
- If you consume a light meal, wait 2 hours before running
- If you consume a snack, wait 30 minutes to an hour before you then decide to run.
These are general guidelines. Not everyone digests food at the same rate, so it's a matter of trial and error to find out how long it's best for you to wait before you start running.
What to eat before training
If you go for a short run first thing in the morning, it is not usually necessary to have breakfast beforehand as your glycogen stores should be enough to fuel your workout.
If you do skip breakfast before your morning run, though, make sure you leave enough time afterwards to have something to eat. It's important that you eat within 30 minutes of finishing your run to allow your body to replenish glycogen stores and rebuild muscles.
During training, you may find that you need to eat a little more, but this is completely normal as your body burns additional calories during exercise.
Some people will need that extra boost before a run and some of the snacks listed below can help provide that little bit of extra energy.
Good foods for training:
- A banana
- A granola bar
- Handful of cereal
Smoothies make another great snack before a run. Take a look at our recipe hub for a whole range of smoothie flavours!
What to eat before a 5k
For runs which last less than 1 hour, or up to a 5 mile distance at an easy pace, runners often find that they have enough stored energy to undertake this type of run on an empty stomach - but how can you guarantee your stored energy won't fail you?
The best thing to do is to have a light snack, 30 minutes before your run, to keep you energised throughout. Try to aim for about 15 grams of carbohydrates and low fibre content in this pre-run snack.
Foods to eat before a short run:
What to eat before a long run
For longer runs of over 60 minutes, or more than 10k, you will need more fuel to ensure that you don't tire out before you are finished. Try to aim for about 30 grams of carbohydrates in this pre-run snack or meal and remember, the more you eat, the more time you need to wait before you start your run.
Foods to eat before a long run:
Other important tips
Try beetroot juice - research shows that, when taken before endurance exercise, beetroot juice could help to improve stamina and oxygen uptake.
Stay hydrated – Make sure to drink water before and during a run, especially if it is a long one, to help replace fluids lost through sweat. Aim to drink 500ml prior to your race so that you are properly hydrated. Drinking any more than this, though, could lead to digestive upset during your run.
Try Balance Mineral Drink – This contains nutrients and electrolytes, including magnesium and potassium, and can help to ease the fatigue and aching muscles you may experience after a race.
Keep your diet varied – Ensure you are getting protein, carbohydrates and healthy fats through your diet and avoid making severe restrictions to what you eat.
Opt for fresh foods – Unprocessed foods including fruit, vegetables, fresh meat, fish and whole grains have more to offer runners nutritionally.
Remember, everyone is different and what works for one person may not work for another. As mentioned before, it's about finding the right balance that works for you, testing different meals and snacks and discovering what gives you the right amount of energy at the right time.
Originally published 20 May 2015 (updated on 5 August 2019)