What to eat on a long run and why it matters Photo: silhouette of a runner filled with fruit and vegetables

What to eat on a long run and why it matters

What to eat on a long run and why it matters
Photo: silhouette of a runner filled with fruit and vegetables

Stuck on what to eat during your long run?

Here’s my step-by-step guide on why you need additional nutrition on a long run, what foods work best and how eating during your long run can help you perform better.

Do you really need to eat during a long run?

If you are planning on running more than 90 minutes, then yes you really do!

Why? Because we need top up our energy supplies to keep going.

The human body is pretty good at storing energy. When we eat carbohydrates, this is converted into glucose and is used straight away for all our immediate energy needs.

Anything left over is converted to glycogen. This is stored in the muscles and liver to be used later when we need it. The amount we can store as glycogen will give us energy for a run of up to 2 hours.

Which means you have plenty of fuel in the tank for a run up to 90 minutes. But once you run longer than that your energy supply starts to dip.

Without topping up your energy, after 90 minutes you’ll probably start feeling a change in your energy levels. Which can mean starting to slow down, your legs can feel heavy, you might get a bit foggy brained. Not what you want!


When to eat during a long run

As you have enough energy to last up to two hours you might think you don’t need to start fuelling until those two hours are up.

But really you need to start topping up a lot earlier, as by the time you’ve run for that long you are already energy depleted.

It’s much better to start fuelling for your run early on so you never get to that critical low energy state.

You can either think of it in time or distance. Eating something every 5k or 30-45mins would be a good guide. But some people prefer to have smaller amounts more frequently.

A lot of it depends on how your gut responds to running and fuelling, which is why it’s important to try different things early into any training you are doing.

How much to eat during a long run

A 2022 review published in Sports Medicine recommends having 60g of carbohydrate per hour or 60-90g per hour for runs over 2.5 hours.

The review also recommends a mixture of glucose and fructose if running over 2.5 hours as GI issues are less prevalent. Something to think about if you find yourself with tummy issues on a run.

60-90g sounds like a lot but most sports energy gels provide between 20-30g per serving. So to get the recommended carbohydrates that would be 2-3 gels per hour depending on the brand.

But be warned, although this is the recommended amount, how your body responds and what it needs might be different. So don’t force yourself to eat 60-90g when you first start running long. Just take enough with you and see what you can comfortably eat to begin with.


What to eat during a long run

Sports energy gels are probably the most convenient thing to eat during a long run.

You know exactly what’s in each serving, they are easy to carry and come in a variety of flavours to keep things interesting.

However, not everyone likes the gels. They can be a bit sticky and the sweetness can be a bit much after too many.

An alternative would be an energy drink. I like Tailwind as it’s a powder you have a bit more control on how strong it is. Which means you can adjust the dilution depending on the weather, distance running and intensity of your run.

But you don’t have to go down the commercial sports gels and drinks route.

Many people love a chewy sweet such as jelly babies, fruit pastilles or liquorice comfits (that last one might just be me!). You’ll just need to check the nutritional info to see how many sweets you need to eat to get your 60g of carbs.

Or, especially if you love trail running, go for real food. Jam sandwiches, Soreen malt loaf, flapjacks, dates, applesauce, boiled potatoes are all things I’ve either eaten myself on a run or have had recommended to me. You just need to be a bit more savvy on how you pack and carry your supplies.

And of course, you can always go for a mixture. That way you are keeping fuelled without getting bored or feeling a bit sickly from all the sweets.


I hope that has helped you understand why you need to fuel for a long run and given you some ideas of what to eat.

Making sure you are fuelling well can not only make the difference between a good run and a bad run but also a good run and a great run.

And if you are wondering what to eat before a morning run, make sure you read my post here.

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