A runner's food guide:
How to boost your energy during a run

BSc in Health Studies, Dip.Nut
Ask Earle

20 May 2015

Firstly let's understand why your energy can fail you

If you run for less than an hour, you’re unlikely to need to eat or even drink during this time as most of your energy will come from glycogen stored in your muscles. However, for longer runs, especially those over two hours, you might need to top up your fuel.

Your body has a limited supply of glycogen available to fuel your muscles and these reserves typically only last for up to 2 hours. During the first hour of exercise, most of your energy comes from stored glycogen in your muscles. 

This all depends on the intensity of the exercise. In high intensity exercise, glycogen stores can be depleted after 20 minutes and in low intensity exercise, they can last for up to 90 minutes. However, in a training run, you are unlikely to need to refuel during a 1 hour run, unless the first part has been very high intensity. 

After this, your muscles start to get their fuel from your blood sugar, which again comes from stored glycogen, but this time from your liver. The glycogen from the liver is also a limited source (unless refuelled) so once it’s been used up, your blood sugar level falls and so too does your energy.

When to refuel during a run

There are several things you can eat and drink during longer runs to help prevent you from running out of energy and to help boost your performance. Eat 30 minutes into exercise so that later in the run the energy is already there to be called upon – be PROACTIVE rather than REACTIVE.

When it comes to drinking, you may want to drink little and often rather than gulping down a whole bottle all at once.

The best foods to eat during a longer run

what to eat during a run

If you’re prone to energy dips during longer spells of running, carry with you and eat small amounts of foods that are full of energy and easy to digest. High-GI carbohydrates are best at this time as they will top up your blood glucose quickly, fuelling the muscles that need them.

Energy bars

Energy bars, as the name suggests, are designed to give a good boost of energy whilst on the go. We’d recommend buying some that are free from junk like refined sugars and artificial sweeteners. Pulsin have some great protein bars, or you could try Squirrel Sisters for something even simpler – these bars contain just a few ingredients such as dates, cashews and cacao powder.

You can even make your own from similarly simple ingredients! Try these tasty cinnamon and chia seed energy balls – they’re really easy to make and provide lots of energy for your run! 


Bananas are popular among athletes for good reason. They’re quick and easy to eat and they provide a good amount of carbohydrates without the tough fibre of, say, apples. After all, you’re looking for something easy to digest, and soft, squishy bananas do just that!


High in calories and light on the stomach, raisins make a great snack for refuelling during a run. Their size means you can eat a couple here and there during your run, rather than having to eat a whole piece of fruit, which could cause digestive problems if you aren’t used to eating on the go.


Pretzels are high in refined carbs (which in this case is good because it releases energy quickly), as well as some sodium which helps to replace lost electrolytes. 

Energy gels

Isotonic energy gels are a combination of water and food and are ideal for providing fast energy boosts. They provide glucose directly into your bloodstream and are an easily absorbed form of carbohydrates. They’re easy to carry in your pocket, and easy to snack on the way. However, they can contain lots of preservatives and artificial flavourings so we wouldn’t advise you consume these regularly!

What to drink during a run


Dehydration usually only occurs on runs lasting more than an hour, so you may find that you don’t have to drink during runs of less than an hour. However, if you do, plain water is a good choice.

If you’re running long distances or running in hot temperatures, it’s very easy to become dehydrated and consequently fatigued. That’s why staying hydrated is so very important as it helps to replenish the fluid lost by your body through sweating and also to maintain your endurance.

Balance Mineral Drink

If you’re running for longer than an hour, or taking part in more intense runs such as a marathon, you may also need to replace electrolytes, which are lost when you sweat. Electrolytes help you retain fluids, maintain hydration and also prevent muscle cramps.

Balance Mineral Drink provides a fantastic alternative to electrolyte-boosting sports drinks, which are often full of chemicals. It contains key electrolytes such as calcium, potassium and magnesium that can be quickly lost during longer runs.

It comes in handy sachets so it’s really easy to add to your bottle of water to sip on during your run. 

Coconut Water

Coconut water also contains electrolytes, making this another good substitute to sports drinks.

Beetroot Juice

Research suggests having some beetroot juice before endurance exercise could help to improve our stamina and oxygen uptake! Read our blog on this to find out more.

How do you boost your energy during a long run or race?

Atrogel – Arnica gel for muscle and joint pain


£ 7.25

Buy now

Arnica gel for relief of muscle pains, stiffness, sprains and bruising. 100ml size available.
More info

Biotta Beetroot Juice


£ 3.99

Buy now

Biotta Beetroot Juice is simply 100% organic beetroot juice, with no added extras.
More info

What's being asked

I have knee pain while I’m running, how can I prevent this?

Knee pain is pretty common while running, but it is also easy to prevent! Check your footfall when ...
Read more >

I have been cycling for several months now and I have developed a pain in my left hip. What could be causing this and how can I fix it?

Hip pain while cycling can occur through over-training or stiffness in the hip joints. Make sure ...
Read more >

Should I eat breakfast before running?

This depends on the length and intensity of the run, if you are running for under an hour generally ...
Read more >

Cherry and Almond Protein Balls

These tasty protein balls are the perfect pre- or post-workout snack!

Get the recipe

Here's what I recommend

As the A.Vogel Muscles and Joints advisor, I recommend Atrogel® Arnica gel to ease stiff, sore muscles after exercise.

Learn more

Did you know?

Peanut butter is a great food to fuel up on before a 5K or 10K because of its low GI, high carbohydrate and high protein content.

What to eat before a 5K or 10K

Recover the right way!

Balance Mineral Drink helps to replace electrolytes and reduce fatigue, making it the perfect post-workout recovery drink!

Learn more

Improve your flexibility!

Join Hetty and Martin in the A.Vogel gardens to improve your flexibility.

View flexibility videos

Healthy & nutritious dinner ideas

Get new recipes in your inbox every week. Sign up now