Ultramarathon Nutrition Guide and Tips

April 24, 2023

Nick Hancock


Ultramarathons present unique challenges in terms of nutrition due to their extreme nature and varying conditions. With race distances that exceed the standard marathon distance of 26.2 miles and go into the hundreds, these events push the limits of human endurance and demand a higher level of nutritional preparation. Developing an effective nutrition plan is crucial for success in these events, as it can significantly impact performance, recovery, and overall health. Ann Transon, top ultra runner, once said "Ultramarathons are basically an eating and drinking competition with some running involved!"

In this blog post, I'll provide tips on how to implement the latest research findings on ultramarathon nutrition to ensure you're well-prepared for your next ultra-endurance race. I'll cover topics such as personalising your carbohydrate intake, training your gut for optimal performance, creating an individualised nutrition plan, and developing effective hydration strategies. By applying these insights to your training and race day preparation, you'll be better equipped to conquer the physical and mental challenges that come with ultramarathons and achieve your goals.

For my own take on my fuelling, check out my blog on long run nutrition

Personalise Your Carbohydrate Intake

Experiment with different carbohydrate sources

The ideal way to consume carbohydrates during an ultramarathon depends on factors like temperature, altitude, and trail conditions. Experimenting with both fluid and solid carbohydrate sources during training sessions will help you determine what works best for you under different conditions.

Fluid carbohydrates

Fluid carbohydrates can be found in sports drinks, gels, and chews - I personally prefer Torq products and proud to be part of their performance consulting coach team! They are easy to consume and digest, making them a popular choice for many ultrarunners. These sources are particularly useful in hot conditions when hydration is a top priority. Be sure to test various brands and flavours to find the ones that you tolerate best and enjoy the most. Also, consider the concentration of the carbohydrate solution in your chosen sports drink, as some athletes may prefer a more diluted mixture to avoid gastrointestinal issues.

Solid carbohydrates

Solid carbohydrate sources include energy bars, fruit, and other portable, calorie-dense foods. These sources can be more satiating and may help maintain energy levels during longer, colder races where appetitet ends to increase. Test different solid carbohydrate options during training runs, paying attention to factors such as taste, texture, and ease of consumption while on the move. Some ultrarunners may prefer homemade options like rice cakes, sandwiches, or energy bites to store-bought bars and gels.

Balancing fluid and solid sources

Striking the right balance between fluid and solid carbohydrate sources is crucial for optimising energy levels and preventing gastrointestinal distress. A good starting point is to aim for 30-60 grams of carbohydrates per hour during an ultramarathon, gradually increasing this amount as you become more experienced and can tolerate higher intake levels. Listen to your body and adjust your carbohydrate in take based on how you feel duringtraining runs, noting any changes in energy levels or gastrointestinal comfort.

Planning for race day

Once you have identified your preferred carbohydrate sources and determined the optimal balance of fluid and solid options, it's important to incorporate this plan into your race day strategy. Familiarise yourself withthe aid stations along the course and their offerings. If your preferred carbohydrate sources are not available, consider carrying your own supplies in a hydration vest or belt. Additionally, factor in any potential changes in weather or terrain that might affect your carbohydrate needs or preferences during the race.

Personalising your carbohydrate intake is essential for success in ultramarathons. By experimenting with various fluid and solid carbohydrate sources, you can determine the ideal balance that works best for your body and the specific race conditions. Remember to practice your nutrition strategy during training runs and adapt your plan as needed for race day. By doing so, you'll be better prepared to tackle the unique challenges that come with ultramarathon racing.

Train Your Gut for Optimal Performance

Practice with various fuels

Training your gut involves practicing with various types of fuel and determining your hydration needs during training sessions. This will help you avoid any unpleasant surprises on race day. To effectively train your gut, experiment with different energy sources such as gels, chews, bars, whole foods, and homemade options. By trying a variety of options, you'll be able to identify which fuel sources work best for you and how much you can comfortably consume during long runs. It's also important to practice consuming fuel at different points during your run, as your stomach's ability to tolerate certain foods may change as you progress through your training session.

I personally like to start off with savoury foods earlier as this usually takes longer to absorb, but also extends my ability to eat sweeter stuff for longer!

Focus on timing and frequency

Another key aspect of training your gut is learning how often to consume fuel during an ultramarathon. A general guideline is to consume carbohydrates every 30-45 minutes, but individual preferences and needs may vary. Experiment with different timing and frequency patterns during training to find what works best for you. Pay attention to how you feel during and after your runs, and adjust your fuelling strategy accordingly.

Train for diverse conditions

Ultramarathons often take place in a variety of environments and weather conditions, so it's essential to prepare your gut to handle different scenarios. For example, your ability to digest and absorb nutrients may be affected by factors such as altitude, humidity, and temperature. To train your gut effectively, incorporate different conditions into your training regimen, such as running at high altitude or in extreme heat or cold.

Adapt to temperature extremes

Cold temperatures may require more solid or warm foods, while extreme heat might increase your preference for liquids or lighter-tasting flavours. Practice consuming different types of foods in various temperatures to identify your preferences and avoid palate fatigue. For example, you may find that warm broth or oatmeal is more appealing during a cold-weather run, while fruit or icy electrolyte drinks may be more refreshing in hot conditions. By training your gut to handle a variety of temperatures, you'll be better prepared for whatever race day has in store.

Develop a pre-race routine

In addition to practicing fuelling during your runs, it's essential to establish a pre-race nutrition routine. This includes determining what to eat in the days leading up to the event, as well as your meal on race day morning. Aim for easily digestible, carbohydrate-rich foods that you've tested during training to minimise the risk of gastrointestinal distress. Your pre-race routine should also include hydration strategies, ensuring you start the race well-hydrated.

Training your gut is a crucial aspect of preparing for an ultramarathon. By practicing with various fuels, focusing on timing and frequency, training in diverse conditions, adapting to temperature extremes, and developing a pre-race routine, you'll be better equipped to handle the nutritional demands of an ultra-endurance event and minimise the risk of gastrointestinal issues on race day.

Develop an Individualised Nutrition Plan

Here are some of my own favourite foods for Carb Loading!

Consider unique race factors

General nutrition guidelines for endurance exercise might not always be practical for ultramarathons. To create a nutrition plan tailored to your specific needs, consider factors such as distance, course terrain, environmental conditions, and available support. For example, a race that takes place at high altitude may require adjustments to your carbohydrate and fluid intake to accommodate for the increased energy demands and decreased appetite. Similarly, a race with limited aid station support might necessitate carrying additional nutrition supplies. By taking these factors into account, you can develop a plan that optimises your performance and minimises the risk of nutritional deficiencies or gastrointestinal issues.

Assess your energy needs

To create an effective nutrition plan, you'll need to have a clear understanding of your energy needs during an ultramarathon. Factors suchas your weight, running pace, and race duration will influence the number of calories you'll require. As a general guideline, aim to consume 200-400 calories per hour during an ultramarathon, but remember that individual needs will vary. Monitor your energy levels during training runs to fine-tune your caloric intake and find the optimal balance between fuelling and gastrointestinal comfort.

Diversify your food options

Incorporate a variety of food options into your nutrition plan to ensure you're consuming a balanced mix of macronutrients (carbohydrates, fats, and proteins) and micronutrients (vitamins and minerals). This not only helps you meet your nutritional needs but also prevents palate fatigue, which can lead to reduced food intake and compromised performance. Experiment with different flavours and textures, and include both store-bought and homemade options to keep your taste buds engaged.

Test your race day nutrition

Incorporate your race day nutrition plan into your training sessions to identify potential gastrointestinal issues and ensure your gut is adequately trained. Simulate race conditions as closely as possible, including terrain, weather, and race pace, to gauge the effectiveness of your nutrition strategy. Pay close attention to how your body responds to the foods you consume, and make any necessary adjustments to your plan based on your observations. By practicing your race day nutrition, you'll increase your confidence in your fuelling strategy and minimise the risk of unexpected issues during the event.

Developing an individualised nutrition plan is a critical component of ultramarathon success. By considering unique race factors, assessing your energy needs, diversifying your food options, and testing your race day nutrition, you'll be better equipped to tackle the nutritional challenges that come with ultra-endurance events and optimise your performance on race day.

Hydration Strategies for Success

Monitor thirst cues

Pay attention to your body's thirst cues and assess your hydration needs during training sessions to develop a hydration strategy that works best for you. Thirst is a reliable indicator of your body's hydration status, but it's important to remember that, in some cases, thirst might not be triggered until you're already experiencing mild dehydration. To stay ahead of potential dehydration, practice drinking fluids at regular intervals during training, and fine-tune your strategy based on how you feel and perform during your runs. I personally drink every time my mile beeper goes off on my watch!

Estimate fluid loss

Another useful strategy for determining your hydration needs is to estimate your fluid loss during training. To do this, weigh yourself before and after your runs to calculate the difference in body weight. Each pound of weight loss corresponds to approximately 500ml/16 ounces of fluid. Use this information to determine your fluid consumption rate and make adjustments as needed to maintain optimal hydration.

Choose the right electrolytes

In addition to water, it's essential to consume electrolytes during an ultramarathon to maintain proper fluid balance and prevent conditions like hyponatremia (low blood sodium). Key electrolytes include sodium, potassium, magnesium, and calcium. Experiment with different electrolyte supplements or sports drinks during training to find the one that works best for you. Be mindful of the concentration of electrolytes in your chosen products, as too high or too low levels may negatively affect your performance.

Precision Hydration are leading the field in this area. Check them out to get your electrolytes in balance!

Practice hydration techniques

Test various hydration methods, such as using hand held bottles, hydration vests (I highly recommend the Salomon ADV series), or aid station supplies, during training to find the most comfortable and efficient approach for you. Each method has its pros and cons: handheld bottles offer easy access to fluids but may feel cumbersome, hydration vests distribute weight evenly but might cause chafing, and relying on aid stations may limit your choices but allows you to carry less weight. Experiment with different options to identify the best fit for your needs and preferences.

Adapt to race conditions

Weather and environmental conditions can significantly impact your hydration needs during an ultramarathon. For example, hot and humid conditions may require you to consume more fluids and electrolytes, while cold temperatures might lead to reduced fluid intake. Practice hydrating in various conditions during training to develop a flexible hydration strategy that you can adapt as needed on race day.

Developing effective hydration strategies is essential for ultramarathon success. By monitoring thirst cues, estimating fluid loss, choosing the right electrolytes, practicing various hydration techniques, and adapting to race conditions, you'll be well-prepared to tackle the challenges of staying properly hydrated during an ultra-endurance event.Proper hydration is key to optimising performance, preventing injury, and ensuring a safe and enjoyable race experience.


The key to successful ultramarathon nutrition is planning, identifying potential issues, and practicing your plan during training sessions. By implementing these tips and taking into consideration the unique demands of ultrarunning, you'll be better prepared to tackle the challenges that come with these extreme endurance events.

Happy running!

Author: Nick Hancock is a UESCA Certified Ultrarunning coach and UK Athletics Coach in Running Fitness (CiRF) and has coached many busy professionals and parents to achieve finishes, top-10s and podiums in events such as London Marathon, Manchester Marathon, Amsterdam Marathon, UTMB, UTS, Centurion events, Endure24, Backyards and many more. Host of the Maximum Mileage Running Podcast and author of the Ultimate Cookbook for Runners

He can be found on Instagram @runwithnick

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