top of page

What to eat on your long run?

What to eat before your long run?

It can be difficult to know what exactly what you should be eating before your long run. How many carbs? Or should you go low carb? What about hydration, how much water should you have? In this post, we’ll explain how and what you should be eating to fuel your long run correctly.

Carbohydrates are the preferred fuel for running, however, the amount you need for each session will depend on its duration, intensity and type highlighted by the fuel mix. For longer and faster runs, there is a clear link between a drop in carbohydrates and exercise performance whereas easier efforts won’t need the same fuelling.

VO2 Max testing enables us to measure your carbohydrate and fat burn at different intensities helping you put together a more accurate fuelling plan.

Find out more about metabolic testing at

To keep things simple, aim to have enough kcals from carbohydrates to fuel the whole of your training sessions, on top of your typical requirements (kcals/macros) for the day. Carbohydrates are needed for daily activities too! There will be exceptions to this rule if your goal is weight loss, or the purpose of the session is to instigate metabolic adaptation through training under low carbohydrate conditions (

Ok so what should you eat before your run?

Use your long, faster runs as a time to practice your race day nutrition. This allows you to train your gut and help your body to get used to taking on carbohydrate when you’re running. As you get closer to your event you can experiment with taking on more carbohydrate to test your tolerance levels. Fuelling for your long runs should include practicing your pre race breakfast, intra workout nutrition and post run recovery. Note down what you eat and how you feel to fine tune race day plan. Mirror this plan for every long run in training.

Your pre run meal

Your pre run meal is crucial to ‘top off’ depleted carbohydrate stores and ensure you have enough fuel your session.

Try and eat a balanced meal 2-3 hrs before your session. This gives you plenty of time to digest your food and avoid any stomach discomfort. Look to include foods that you would typically eat like porridge oats, bagels, toast and cereal for breakfast, or pasta, bread and rice for lunch. Try and avoid foods that are high in fat and fibre to reduce any gastrointestinal (tummy) problems. Spicy or acidic foods may also lead to discomfort during running. The key here is to practice your pre-race meal so you can find a setup that you know works well.

You may also consider a smaller snack such as a sports drink, carbohydrate chews/gel, fruit, or a cereal bar 15-45 minutes prior to your session. This can help top up blood glucose and help ensure you have plenty of energy.

Can’t eat before you train?

If you are training early and a big meal is impractical, fuel your session with a large carbohydrate meal the evening before. In the morning have a smaller liquid or semi liquid snack like a smoothie, shake or yoghurt that can be easily digested .


A 2% drop in body weight due to water loss can hinder both cognitive function and exercise performance. Although there are individual differences amongst athletes, we recommended that you drink around 5-10ml/kg of bodyweight 2-4 hours before exercise.

During your run

Runs that last beyond 60-90mins will deplete your glycogen/carbohydrate stores

For sessions lasting longer than 60 mins at a high intensity (> 70% VO2Max), aim to consume 30-60g of carbohydrates per hour in a 6–8% carbohydrate-electrolyte solution (around 200ml) every 15 minutes. Look for foods, drinks, and gels that are easily digested and won’t cause any stomach complaints.

For events lasting >2.5 h, higher carbohydrate intakes of 60–70 g/h, and up to 90 g/h if tolerable are associated with improved performance. The intensity of the session and daily kcal targets will affect this number. If your goal is weight loss then you may consume less and only aim for 20g/h.

Combining your carbohydrates

Research shows that combining different types of carbohydrates (glucose and fructose) enables you to ingest more (90g/hr) compared to using one sources. This is because glucose and fructose use different transporters for absorption. For events lasting longer than 3 hrs, it is recommended to combine these two carbohydrates to help increase absorption rates, which can lead to improvements in performance.

Look to consume a 2:1 glucose: fructose ratio, however many sports drinks will already have that ratio so it’s not something worth worrying about.

You should also be aware that these numbers are only guidelines as the tolerability of the higher carbohydrate numbers will vary between athletes. Eating this amount of carbohydrates can also cause GI distress so you should routinely practice a strategy that works well for you. Testing of these higher numbers is the only way to see if these numbers can work for you.

In a nutshell

Do you need more help with your nutrition?

Box Nutrition offers nutrition coaching and VO2Max Testing. Get in touch to see if we can help or check out


Featured Posts
Book Your Metabolism Test
White Minimalist Weight Loss Instagram Post .png
Official HYROX Gym Instagram.jpg
Get The Book!
book mockup.jpg
VO2Max Testing
Follow Us
  • Facebook Basic Square
  • Twitter Basic Square
  • Instagram Social Icon
bottom of page