Okay – this is a big one – what do I eat when I am running?

Two main points; the first is a simple rule to follow; slow carbs before fast carbs after.

The second one is harder – you must get to know your body and use yourself as a guinea pig, and practise!

So, lets start simple:

What are slow carbs?

Slow carbs are carbohydrates that take longer to go through your system, they are also known as complex carbs. They are closer to their original form.

Examples include:

  • Brown pasta
  • Brown rice
  • Brown bread
  • Starchy veggies like potatoes, other root veggies
  • Pulses and legumes

Slow carbs provide a slow release of energy as your body digests them, so this can help keep you sustained as you run. A good pre-run fuel up should definitely include slow carbs so that your energy rises as you begin to work your body harder.

What are fast carbs?

Fast carbs (also known as simple carbohydrates) go through your system quickly and efficiently, giving you a burst of energy.

This quick energy gain is brilliant for putting fuel back into your body post-run.

But not so good before, as what happens is your energy peaks, then you can crash (and you don’t want to crash while you’re running!)

Fast carbs are often refined in some way, such as:

  • White rice
  • White pasta
  • White bread
  • Processed foods; crackers, biscuits etc

My ideal post run meal is BBQ ribs and Chips! Yummy! (it's got loads of protein, fat, fast carbs and sugar! yeah!)



Your main challenge as a runner is keeping your energy at optimum levels avoiding, if you can, very high peaks and troughs. You’re thinking – ok Nic so I chow down on my slow carbs with a bit of protein and fat and loads of water, then I run, then when I’m done it’s white pasta all the way and I’m golden!


Your body can store approx. 1-2 hours of fuel (call it 90 mins to be safe) so if you eat 45 mins before you start your distance run, you’ve got about 45 mins worth of fuel onboard. I’m not saying you’ll conk out after this time – but you’ll start to feel the depletion. YES there are other areas of fuel your body can draw from (such as stored fat) but this isn’t as efficient. This is why if you are running for many hours at a time you need to eat every hour.

Let’s say you’re planning to run a marathon. Rounding it out evenly lets say you expect it to take you 5 hours to complete.

You eat 45 mins before so you don’t throw up at the start line.

You’ve got 45 mins fuel in you.

Allow some time for digestion depending on what you’ve got. (high sugar carbs will be easier to absorb – like fruit or gummy bears).

  • The race starts at 10am
  • 10.45am eat
  • 11.45am eat
  • 12.45pm eat
  • 1.45pm eat
  • 2.45pm eat
  • 3pm – finish the race

So you can see if you up your speed you won’t have to take so much! If you’re faster you’ll need less fuel! It’s all about time!

When planning your run it’s worth taking the time to consider what you should eat before your run and what you’re going to take with you on your run. This is why energy bars and gels are so popular, they take up very little space and provide a big efficient burst of energy. BUT don’t think all your problems can be solved with gels (often they are quick bursts so you need to ingest one every 15 mins!) you’re rethinking what to carry now aren’t you?

What you take with you needs to be lightweight, easy to carry in a pouch, something that’s not perishable and packed with slow carbs to keep you going. And hopefully something you can eat while running/walking. There’s some homework for ya!

The good news is there’s loads of options:

  • Flapjacks
  • Smoothes
  • Energy bars
  • Even sandwiches!

Try it out and see what works for you!

Post-run is just as important.

Think of your run as depleting your body of fuel, and damaging it a little bit (all over) so you must immediately rehydrate, replace fuel and provide sources of repair; protein, to get those muscles functioning in tip-top condition again. A good post-run would be protein, fast carbs and a good source of fat. So something like chicken, white pasta and avocado hits those three main points.

Often we don’t feel hungry after a long run but ravenous after a short one.

This has a lot to do with the ‘mode’ that your body has gone into. I can’t explain I very well here but the podcast that Jennifer Bulcock (our guest nutrition consultant) did for the group a few years ago goes into great detail about this. I will post the link!



Now to the second (harder) point

  • You know your body
  • You know what feels good and what doesn’t
  • You have to practise.

How short a space can you leave after eating before you run?

Try eating 1 hour before, 30 mins before, 15 mins before? Write down what you did, how far you went, how long you ran for and how it felt. Did it make you throw up? Or feel sick? If it’s a no see if you can reduce it further.

The closer you can get to eating then running the more your running can go over that 1-2 hours of stored fuel (and the less you have to carry with you)


How big a meal can your tummy take?

Experiment with sizes before you run. Try running after only a light snack, then see if you can eat more.

Again record what you did so you can figure out what works best for you.

Try not to change both things at once – sort the timing first then experiment with how much fuel.


If you want to get REALLY technical log your pre-run food in MyFitnessPal so you can see how much you’re taking in in kcals – if you keep doing this and logging how the run felt (did you hit any walls, feel sick? Legs not working? Or flying) then you can work out what your optimum calorie intake is for how you run!

So there you have it!

Lots to think about when fuelling for distance runs both before and after.