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The Importance of Fuelling for Ultra-Distance Events

Salomon ambassador and sports dietitian, Alexandra Cook, explains the importance of fuelling for ultra-distance events.


Training and racing for an ultra is tough.  However, an ultra is not just about running, it’s about also about planning. Planning on how you are going to tackle the distance but also on how you are going fuel it. The main aim as an ultra runner is to maintain a high energy output over a long time. During training and the race, energy expenditure is extensive, so you must pay as close attention to a nutrition plan as you do your training schedule to make the most of your efforts.


Nutrition for day to day training is not about making things complicated or following a meal-by-meal set plan. The subtlest changes can have a significant affect on how well you progress through your training plan. The first aim is to get your basic , day to day nutrition right, ensuring you have a well-balanced diet that meets your daily requirements.  Keeping a food diary can help you identify things in your daily diet that you may be missing out on.

After you have recorded a few days ask yourself these questions:

  • Am I eating three meals a day?  

  • Am I eating a balance of food groups at each meal: protein, carbohydrate, fats and vegetables/salad? 

  • Am I drinking enough water during the day?  

  • Am I eating five to seven portions of fruit and vegetables a day? 

  • Do I have large gaps between eating and training?

If you find you are falling short in an aspect of your diet, focus on one thing for a week. For example, drink more water, have breakfast every day or increase your fruit and vegetable intake. Being consistent with that change will eventually lead to you changing your habit, at which point, you can look to start tweaking other areas of your diet that might need improving.


Training regularly means energy demands are high, meaning, calorie intake is important to get right, however a generalised suggestion for the masses is not possible. In simple terms, the more energy used during the day and during training the more energy needed to maintain energy balance to avoid energy deficit. If training volume is increased without addressing intake, the ability to train well reduces and overall health may suffer.



Macronutrients are the main nutrients that fuel and help recover from training. These are carbohydrates, proteins and fats. The amount you need is dependent on your fitness, size, and the intensity and volume of training.

Carbohydrate are the main source of fuel the body uses when you run. It will also use fat, but carbohydrate is the preferred source as the body finds it easiest to use for energy. The shorter the exercise burst and the higher the intensity, the more the body will use carbohydrate as opposed to fat. Essentially the more training you are doing, the more carbohydrate you need on a daily basis. Guidelines state you should be aiming for approximately 5-7g of carbohydrate per kg of body weight, if training for less than one hour per day. So, for a 70kg runner, this would be between 350-490g of carbohydrate per day. The higher the training volume, the higher the demand for carbohydrate, so look at your training week as a whole and decide what you feel is right for you.

Here are some examples of what 50g of carbohydrate looks like:

Weetabix75g3 x biscuits
Rice (cooked)175g4 tbsp
Pasta (cooked)225g8 tbsp
Bread100g3-4 slices
Jacket Potato175g1 medium
Banana225g2 large

Protein is the main nutrient for muscle protein synthesis  (the process that instigates muscle repair and adaptation). A common thought is that protein is primarily needed just after exercise. This is true in a sense but a more regular intake of protein at every meal, as well as some high-protein snacks, is vital to ensure this process is supported. An endurance runner should be aiming for between 1.2 - 1.8 g protein per kg of body weight per day. Key here is to aim for a portion of between 15-20g of protein at each meal to help you hit your daily target rather than big protein dumps over two meals.  Always ensure you have protein portion at each meal, for example, eggs, fish, chicken, beans  / pulses, quorn.

Here are some examples of what 20g of protein looks like:

Beef75g2 Medium Slices
Fish Fingers100g6 Fish Fingers
Eggs150g3 Medium-sized
Milk600ml1 pint
Cheddar Cheese75g2 Matchbox-sized Pieces


Ensuring training is supported is not just about what you eat, it’s about when you eat.  To get this right, you need to plan. Food consumed before exercise is only readily available for energy once it has been digested and absorbed. Therefore, you need to ensure you have good fuel stores in place and you time your food intake so that it becomes available during your exercise. The availability of energy depends on a few factors such as type and amount of food you are eating. For example, food higher in fat and protein take longer to digest and hence will take longer for energy to be available to fuel exercise. Also, larger portions of food take longer to digest than smaller amounts.  Aim to have a carbohydrate rich meal 2-4 hours with moderate amounts of protein and fat before you train or race.  The larger the meal the longer you need for it to digest and ensure energy is available for exercise.  You might also want to take on a high-carb snack an hour before training to top up your blood sugars for example a banana or a cereal bar are all good options. It is a good idea to experiment around training and see what works best for you.

How you recover after training has a huge impact on your overall performance, helping you get back to your previous form and adapt to the training load.  Nutrition plays a pivotal role in this process, with what you eat and what time you eat it impacting the rate at which you recover.

Carbohydrate and protein are the main nutrients we need to recover. Protein, as previously discussed, will help with muscle repair, while carbohydrates will help to replenish muscle glycogen stores which have been depleted during training. If you don’t replenish those stores, your next training session could be really hard going. Rehydrating is also a focus point. Dark-coloured urine after training or racing is to be expected but the aim is to get it nice and clear again within a few hours.

Aim to follow the ‘3 Rs Of Recovery’ after every training session.

  1. Rehydrate with water or / and electrolyte drink
    You need to take on fluid at a rate that you are not peeing it straight out! As soon as you have finished training/racing, drink 500ml of fluid. After that, drink little and often until your urine is clear, or you have reached your pre-run weight. 
  2. Refuel with carbohydrates (but no need to over-compensate)
    Ensure you’re eating enough carbohydrates (as previously outlined) within a well-balanced snack, or meal, within an hour of finishing exercise.
  3. Rebuild with protein
    Get into the habit of having approximately 20g protein within your post-training snack or meal, and then regularly at each meal and snack for the remainder of the day.





The longer we can save our stored carbohydrate, the better we will be fuelling when we run. If we can keep our blood sugar levels topped up, we can keep saving our stored carbohydrate for later. Therefore, it is important to maintain your energy levels as early as possible.  If you are waiting to take your first gel or drink until an hour into your run, your glycogen stores will already be getting low. The key is to start early at about 20 - 30 minutes in. Although you won’t necessarily be feeling low on energy, topping up the tank from the word go will only benefit you later in the race where fuelling may become harder due to fatigue and potential stomach problems.


The “Gold Standard” for carbohydrate consumption during exercise is approximately 60g per hour (based on the ability of 1g/min carb absorption) with a maximum possible absorption of 90g/hour if taken in a 2:1 blend of glucose:fructose (known as dual carbs ). This combination increases absorption rate over time, resulting in very high oxidation rates. There has even been a suggestion of higher amounts being tolerated when a study back in 2020 (1)  published findings on a small co-hort of elite mountain marathon runners looking at the effects of 120g/h of carbohydrate during a mountain marathon . It showed that some of the runners could tolerate this massive amount of carbohydrate (equivalent of 5.5 gels) and showed less muscle damage 24 hours post race compared to the group taking lower amounts of carbohydrate.  Although quite an exciting finding in the world of sports nutrition, more studies need to be done.

Many ultra runners like to take protein alongside carbohydrate during races but does it improve performance? A review in the Journal of Sports Medicine (2014) concluded that although protein ingestion during prolonged exercise may inhibit muscle protein breakdown, it does not further enhance performance capacity when compared to the ingestion of ample amounts of carbohydrate alone.

So we are clear on the science that it is possible to absorb between 60-90g carbohydrate (and possibly 120g) over the hour and protein ingestion alongside carbohydrate won’t necessarily improve our race performance but how does this translate into reality?

Tolerating 120g of carbohydrate per hour for the length of an ultra for most runners is unlikely.  90g of carbohydrate per hour is possible but requires well planned gut training and is certainly not for the weak stomached! The reality of it is, during ultras we need to survive and to survive we need to be flexible. If you aim to consume 60g of carbohydrate an hour, you will find yourself in a strong position. Unless you are among the elite few, speed is not of the essence but keeping one foot in front of the other is the aim of the game. If you go slowly enough, for long enough, its gets to the point where you can use anything for fuel, just so long you take in the calories and your stomach can tolerate it. Early on you in the race can survive on gels and other carbs but after 4 hours taste fatigue can set in and your body starts craving more. Although, unlikely to improve performance, adding one part protein to four part carbs may keep hunger at bay (protein takes longer to digest) and may provide some “comfort” six hours into a long race.


This is where individuality rules! First up is to experiment and see what works for you. Gels, energy chews, sport drinks, bars, real food…it is personal choice and down to tolerance and taste. Sports products are designed for fast absorption and ease of use but some people dislike them and find real food is the way forward. Sports drinks tick both boxes of fuelling and hydration and are a good base for your fuelling plan. If you are doing a race that provides drinks and food, find out what they are and train with that specific brand. This may mean that you can rely on the pit stops rather than carrying your own. Additionally find out what they supply at the check points and aim to use these for your refuels.

30g/hr1 Energy Gel or 1 Energy BarSmall Sports Drink (250mls)
60g/hr3 x Energy ChewsBottle of Sports Drink (500mls)
90g/hrEnergy BarBottle of Sports Drink (500mls)

Over the ultra distance taking on fluids is vital for performance. For a successful plan though we don’t need to exactly match our fluid output with input. A degree of dehydration is to be expected but anything more that causes anymore than  3% weight loss by the end of the race you could see a reduction in performance.  Therefore target your fluid plan so you loose no more than 3% of your body weight.

For example;

  1. Work out how much fluid you lose / hr by weighing yourself before a 60 mins run and after  - 1 kg represents 1000 ml (remember this varies significantly over time and environment).
  2. Multiply that by the length of time running - for example 8 hours  =1000ml x 8 =  8000 ml
  3. Allow for 3% weight loss-70kgs runner  = 2.1kgs (2100 ml)
  4. Total aim for approx hydration  = 8000-2100 = 5900 ml
  5. 5900 / 8 hr  = 737 ml / hrs (700-750 ml  / hrs)


  1. The science provides the guidelines but be flexible, as no matter what the science says, you are more constrained on the day by what your stomach dictates.
  2. Find out what products are available on the course / check points , training with them may mean you can rely more on check point nutrition.
  3. Use your long training runs to conduct experiments of how much and what type of fuel you can tolerate.
  4. If new to taking on carbs during running, start with 20-30g carbohydrate per hour, little and often of either single or dual source carbs and aim to work up to 60g/hr….remember your gut is trainable.
  5. Remember to reach 90g/hr you need to be using only “dual” source carbs to reach this amount.
  6. Set your watch time to bleep every 20-30 mins to remind you to fuel.
  7. Start fuelling early whilst the gut is fresh and absorbs carbs easily, things might not be so easy a few hours into the race! 


Alexandra Cook has 14 years of experience as a sports dietitian, a UKA athletics coach and ambassador for Salomon. She is a competitive distance runner with 20 years experience and provides realistic advice as an endurance athlete herself. An athletes plan will not only meet performance needs for your sport but will ensure you are performing your best in all aspects of your life. 

Keen to learn more about fuelling for performance and adventures? Then check out our Nutrition category for more handy tips, advice and recipes.


Welcome to the SportsShoes Nutrition Hub! We’ve teamed up with the experts to bring you the very best advice on the best foods to fuel you and your adventures.

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