Consuming food and fluid on a run can be a new experience for many, and can feel slightly uncomfortable to start with. It's vital to trial eating strategies during longer training runs as this will help train the gut to digest carbohydrates while on the move.


Q: How far or how long can I run without refuelling?

For training runs under 1 hour, there is no need to refuel on the move, as long as you have eaten enough to keep your energy up before setting out.

The focus should always be on fuelling properly before your run, instead of reaching for carbohydrates during. This will come down to the goal for your run. For lighter, lower-intensity training sessions where the goal is to improve your fitness, there is often no need to take on extra carbohydrate during your run. Your body will have sufficient energy from fat and carbohydrate stores.

For harder runs over 1 hour in duration, consuming small amounts of high-GI carbohydrates can help to maintain performance. But remember, this will depend on the goal for your training. If you are 'training low' and trying to adapt to using fat as fuel for training, you should reduce your carb intake during training.

For a race, carbohydrate-rich food and drinks can be an important tool to maintain intensity. Remember, the higher the intensity, the more carbohydrate you'll need.

Consuming carbohydrates during a run should be practiced in the final eight weeks of training for a marathon, to ‘train the gut’ and find out what works best for you.

Easily absorbed carbohydrates also provide important fuel for the brain, which allows the body to keep working harder, especially when muscles begin to tire. Interestingly, research has indicated that using a carbohydrate sports drink as a mouth rinse may help to activate the brain, which could be a useful technique later in the race if you struggle to take on fluids.

Q: What are the best foods to eat on a run to avoid feeling full?

Sticking to easily absorbed, high-GI carbohydrate options should help you avoid discomfort and nausea during a run. Where possible, try to include some carbohydrate-electrolyte sports drinks to meet your fuel and fluid needs.

Q: What are some different options for energy-boosting during a run?

If you already regularly consume caffeine as part of your diet, this can be used in addition to carbohydrates for an energy boost. There are commercially available sports drinks and gels containing caffeine, which can be extremely useful, especially later in the race.

Q: Should I only eat when I feel hungry or should I snack continually during a race?

Don't rely on hunger as a cue to refuel during the race. As a general rule, practice and refine your fuelling during training and find a strategy you're comfortable with. Taking on carbohydrate little and often, for a constant energy supply, is often the most efficient strategy.

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Often the biggest mistakes on race day can be made by trying to take on too much carbohydrate during the race. Aim for 30g of carbohydrate an hour as a starting point and see how you feel – the maximum you will require is 60g/hour – but in practice, most athletes don’t require this amount. Build your strategy in training and find what is comfortable for you.

Carbohydrate drinks are typically the most efficient way to meet these targets, alongside good hydration. Carbohydrate gels will also be readily available on race day and are rapidly absorbed. Small pieces of banana, cereal bars and jellied sweets also can help to offset hunger.

The following will provide around 30g of carbohydrate – see what works best for you and experiment with quantities during training:

  • 500ml bottle of commercially available sports drink
  • 1½ carbohydrate energy gels
  • A small handful of jellied sweets
  • One large banana
  • One large cereal bar or carbohydrate based energy bar (choose a low-fibre option)

Now you know what to eat during your run, get the rest of your training nutrition right:

What to eat before your run
Carb-loading explained
Meal plans for runners
How to stay hydrated

This article was last updated on 20 February 2020 by James Collins.

James Collins is recognised as a leading Performance Nutritionist through his work with Olympic and professional sport. Over the last decade he has worked with Arsenal FC, the England and France national football teams and Team GB. He has a private practice in Harley Street where he sees business executives, performing artists and clients from all walks of life. He is the author of the new book The Energy Plan, which focuses on the key principles of fuelling for fitness.

All health content on is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.


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