Running is a form of exercise, a way of meeting new people, and as a leisure activity, and it is growing in popularity. Depending on who you ask, a long run could be a 10k, a half-marathon, a marathon or an ultramarathon. Technically speaking, a long run can be defined as a sustained effort over a considerable distance, typically defined by runners as a run that lasts more than an hour. However, this can vary based on individual fitness levels and training goals. Some resources report that long runs should comprise 20-25% of your total weekly volume. However, the most popular consensus is that a long run is any run that significantly exceeds your average daily run, pushing the boundaries of your endurance.

Proper nutrition before a long-distance run is crucial as it directly impacts your energy levels, endurance, and overall performance. Eating the right foods at the right times helps ensure that your muscle glycogen (carbohydrate) stores are adequately filled, providing sustained energy throughout your run. This can help prevent mid-run fatigue, optimise your performance, and enhance recovery post-run.

If you are looking to optimise performance and growth for a young athlete, read here for more specific information, as the following guidance applies to adults.

Before a long run, preferably 1 to 2 hours before, eat easily digestible carbohydrates (carbs) and some protein, such as a banana and some low fat Greek yogurt or a slice of white toast with jam and peanut butter. If you are short on time and only have 30 minutes to an hour, having a simple, easy to digest carb source such as a banana, some dried fruit or a carb gel would be ideal.

Should you eat before a long run?

Eating before a run gives you more energy, helps with performance, and can prevent mid-run burnout or ‘’hitting the wall’’. “When you’re training for longer distances, practising your runs with fuel in the belly can optimise performance,” says Karissa Culley, a registered dietitian with UW Medicine. Check out our article on specific nutritional needs before a long run.

‘Carb loading’ is a common term often recommended to people before running a long distance run such as a marathon. It’s often recommended as consuming more carbohydrate whilst reducing some caloric intake from protein and fat, will make sure that your glycogen stores are filled up as much as possible before you start. Glycogen is a form of energy storage in your body. Think of it as a backup battery that your body can use when it needs extra energy. It’s made from the carbohydrates you eat and is stored mainly in your liver and muscles. When you need energy, especially during activities like exercise, your body breaks down glycogen to keep you going.
The need to have a high carb snack or meal pre-run increases when you have eaten relatively small amounts of carbohydrate in the days leading up to a run or have not allowed for adequate amounts of rest and recovery. However, some people confuse carb-loading for overeating, which is not the ideal strategy to improve running performance. You want to balance getting enough food (and fluid) to fuel your run whilst avoiding any gut upset from eating too much.

Is it OK to not eat before a long run?

Some research suggested that if pre-run snacks or meals are regularly skipped in a training routine, then having carbs during your run may offset the negative effects of having an empty stomach on your run.

However, this does not mean that it’s recommended to run on an empty stomach. This same research suggests being cautious if taking this approach as having too many carbs during a run may overwhelm your gut leading to cramping or gut discomfort. In general, it’s recommended to eat before running, especially when you’re expecting it to be a harder training session, as your body will need fuel from carbs. This gives your body the fuel it needs to exercise safely and efficiently.

If you suffer with nausea or feel as though you struggle to digest foods quickly enough before setting off on your run, you might be better suited to fuel beforehand with a glass of orange juice, some fruit or a handful of sweets.

Foods to eat before a long run

  • Bananas

    • Bananas are rich in simple carbohydrates, which is an excellent source of quick energy just before a run, the sugar in the banana will get absorbed quickly in your bloodstream and released for energy consumption for your run.
    • Bananas are also an excellent source of potassium and provide about 15% of the recommended daily value for this nutrient in just one medium banana. Potassium also helps support muscle contractions and prevent muscle cramps.

      Bananas for a long run 

  • Dried Fruits (Dates, Figs, Raisins, etc.)

    • Dried fruits are a concentrated source of simple carbohydrates, which are easily digestible and provide quick energy. The natural sugars in dates, figs, and raisins rapidly enter the bloodstream, offering an immediate fuel source.
    • Additionally, dried fruits are often rich in potassium and magnesium, which support muscle function and help prevent cramps during long runs.
    • However, be cautious of having too much dried fruit whilst running as these are high in fibre, which while fibre is beneficial for digestion in general, too much fibre during a run can lead to gastrointestinal discomfort, including bloating, gas, and diarrhoea.

       Dried fruit for a long run

  • 100% Fruit Juices

    • Natural fruit juices are high in simple sugars and carbohydrates, making them an excellent choice for quick energy before a run. They are easily digested, providing a rapid source of glucose to fuel your muscles.
    • These juices often contain vitamins and minerals like vitamin C and potassium, which support overall hydration and muscle function.

      Fruit Juice for a long run

  • Gels (e.g. Gu, Huma, SIS)

    • Energy gels like Gu, Huma, and SIS are specifically designed to provide quick and easily digestible carbohydrates. They offer a concentrated source of glucose, which is rapidly absorbed, ensuring that your muscles receive a steady supply of energy during prolonged exercise.Gels for a long run
  • Sports Drinks (e.g. Gatorade, Lucozade Sports, Powerade)

    • Sports drinks are formulated to provide a quick source of carbohydrates and electrolytes. They are easily digestible and offer an immediate supply of glucose, essential for maintaining energy levels during long runs.
    • The electrolytes in these drinks also help maintain hydration and prevent cramps.Sports drinks for a long run
  • Smoothies

    • A smoothie made from just fruits or with added yogurt can be an excellent pre-run snack.
    • When consumed 30 minutes before a run, a fruit-only smoothie provides quick-digesting carbohydrates for immediate energy.
    • Adding yogurt and consuming it an hour before a run supplies protein and a slower release of energy, supporting sustained endurance.

      Smoothies for a long run

  • White Bread

    • White bread is high in simple carbohydrates that are quickly converted into glucose, providing a fast-acting energy source.
    • 30 minutes before a run, spreading jam or honey on white bread adds additional carbohydrates, enhancing the energy supply and making it a convenient and effective pre-run snack.
    • Whilst if you have an hour or more before your run, pairing bread with eggs would be an excellent choice for a protein and carbohydrate combination to support muscle repair and maintenance. and provide sustained energy before a long run.
      bread for a long run
  • Bagels

    • A bagel, similar to white bread, when paired with a high carbohydrate spread like jam or honey is rich in carbohydrates, making it a great pre-run meal for sustained energy.
    • The carbohydrates in the bagel provide a steady release of glucose, while the jam offers a quick sugar boost. This combination ensures a balance between immediate and prolonged energy availability.
       bagel for a long run
  • Porridge

    • Porridge is an excellent source of complex carbohydrates and fibre, which provide a slow and steady release of energy.
    • Consuming porridge on its own, made up with milk, or with yogurt, depending on the timing, ensures a balanced intake of carbohydrates and protein.
    • Eating porridge an hour or longer before a run provides sustained energy, while adding yogurt enhances protein intake for muscle support.
      Porridge for a long run
  • Sweet Potato or Baked Potato

    • Sweet potatoes and baked potatoes are high in complex carbohydrates, which are broken down slowly, providing a steady release of energy over an extended period.
    • They are also rich in potassium, which helps maintain electrolyte balance and prevent muscle cramps during a long run.

      Sweet Potato

As a general guideline, it’s recommended to wait 3 to 4 hours after a large meal before running. If you’ve had a small meal or snack, wait a minimum of 30 minutes or preferably 1 to 2 hours before going for a run. Keep in mind that everyone is different, so you should experiment to find what timing works best for you.

Having a combination of both carbs and protein in your pre-run snack or meal has been shown to increase the speed of glycogen recovery when you don’t have a lot of recovery time (i.e. multiple training days), if less than ideal amounts of carbs have consumed, and also is thought to help to reduce symptoms of muscle damage.

Options to consider before a long run:

3-4 hours before 1-2 hours before 30 mins – 1 hour before
Complex carb + protein Simple Carb + protein Simple carb
Overnight oats made up with Greek yogurt and fruit

 

Scrambled eggs wholemeal wrap with roasted red pepper and spinach

 

Sweet potato bowl with grilled chicken and roasted veggies

 

Whole grain peanut butter and jam sandwich

 

Whole grain toast with peanut butter and banana slices

 

Salmon poke rice bowl with pickled veggies

Yogurt and dried fruit granola

 

2-3 dates with peanut butter

 

Fruit smoothie with 150g of yogurt/milk/soya milk

 

250ml glass of fruit juice + 70 ml yoghurt

 

30g cereal (not wholegrain) with 250ml milk

 

A white bagel with jam

1 Banana

 

2 Soreen bars

 

2 Cereal bar (i.e. Rice Krispies bar)

 

2 Medjool dates + 1 Nakd bar

 

250ml 100% fruit juice (no bits)

 

2 carb gels

 

 

Some research suggests that in the ~30 minutes before the start of a long run, you can ‘’pre-load’’ your stomach with fuel from carbs, without any risk of developing what is called reactive hypoglycaemia (i.e. sudden low blood sugar). The general recommendation is to aim for 20-30g of carbs with 90-180 ml of water.

For runners training in high volumes (i.e. over or equal to 8 hrs) of exercise per week you will need more energy to continually replenish your stored glycogen, or carbohydrate. The single most effective strategy to optimise this recovery and sustain fuel for runs in the week is a high carbohydrate diet that can be anywhere from 8-12 g/kg of carbohydrate a day!

If you experience stomach problems frequently, you should avoid spicy foods, and meals that are high in fibre and fat. It may also be worth avoiding dairy based products, or use lactose free products if you are prone to digestive issues. Though we would recommend for more personalised guidance to consider consulting a Sports Nutritionist.

What to eat before a long run in the morning?

When you wake up in the morning, your liver has used up most of its glycogen during the night. Glycogen is important because it helps keep your blood sugar steady, especially during a long run. That’s why breakfast is crucial as it refills your liver’s glycogen stores. If eating solid food is hard before a run, drinking something with carbs, like a glass of orange juice, could be a practical solution.

Many endurance events such as marathons often start in the morning and finding a balance between rest and fuel is important to perform to the best of your ability.

What to eat the night before a long run?

Eating well the night before can help ensure your glycogen stores are full. Consider these options:

  • Whole grain pasta with a tomato-based sauce and lean protein (like chicken or tofu)
  • Brown rice with vegetables and lean meat
  • Quinoa salad with mixed veggies and chickpeas
  • Sweet potatoes with grilled fish or chicken

What should you avoid eating before a long distance run?

Certain foods can cause discomfort or digestive issues during a run. Avoid these types of foods before a long run:

  • High-fibre foods (such as beans and cruciferous vegetables like cauliflower, cabbage and kale)
  • High-fat foods (like fried foods or rich sauces)
  • Sugary foods and drinks (which can cause a quick spike and drop in energy levels)
  • Spicy foods (which can cause gastrointestinal distress)
  • Large meals (which can lead to stomach discomfort and sluggishness)

Is it better to eat before or after a long run?

Eating both before and after a long run is important. Pre-run meals provide the energy needed for the activity, while post-run meals help with recovery and replenish glycogen stores.

After a run, focus on replenishing your glycogen stores and aiding muscle recovery. Good options include:

  • Protein shakes or smoothies made up with Greek yogurt or cow’s milk
  • Greek yogurt with honey and nuts
  • A sliced turkey sandwich
  • A large glass of chocolate milk

By following these guidelines, you can optimise your nutrition for better performance and recovery, making your long runs more enjoyable and effective.

Having support from a dietitian can help with your running nutrition, as well as ensuring that you are eating a balanced and well varied diet. Book a consultation with a dietitian here.

Categories: Blog post

Isabella Alfonso dietitian in London

Isabella Alfonso

Isabella specialises in sports nutrition and weight management. Isabella is able to translate complex nutritional science into practical advice tailored to individuals' goals, dietary needs, and training demands. Isabella has worked with a range of athletes such as swimmers, combat sports athletes and endurance sports athletes whilst at Dietitian Fit, competing at a professional level, amateur tournaments and recreational levels. Having clinical experience both in the NHS and private sector, Isabella has worked with a range of clients with gastrointestinal dietary requirements such as coeliac disease and IBS, oncology, and with professional athletes such as the 2024 Western Australian Women's Boxing Under 60kg State Champion.