Master your marathon with practical nutrition strategies covering carb-loading, race-day fueling, hydration, and recovery. This guide offers actionable advice to help runners of all levels train their gut, avoid fatigue, and optimise performance.

How To Fuel For A Marathon

Source: Miguel A Amutio
 

Whether you’re a seasoned marathon runner or you’re preparing for your first event, diet plays a massive part in being able to go the distance and be consistent. I’m Rachel, here from the Wildfire Sports & Trek team to answer questions around nutrition and marathons, including carb-loading, suggestions for what to eat during race day and how to make sure you set yourself up for recovery afterwards. 

Training for a marathon involves preparing your body to endure the distance, avoid injury, and focus your mind. As senior athlete and author George Sheehan said, “... Competition is against the little voice inside you that wants you to quit”.

By building a solid strategy for fueling, you can get the most out of your performance and subsequent recovery. While getting kilometres in your legs and feet is important, equally so is rest and nutrition. We’re going to dive into the finer details of nutrition throughout this blog. 

Before we get into the Q&A, some things to note:

1. I am not a registered dietitian. While I studied food and nutrition science and have a personal interest in exercise and food, I am not a qualified health professional, and as such, all advice included here is general. Please consider your personal needs, food budget, allergies, medical history, time availability, fitness ability and any injuries, etc. before making changes to your diet or exercise regime. Consult your GP or a dietitian if you have any concerns/questions/special requirements.
2. We know a lot about what works for most people when it comes to general nutrition and sports nutrition. However, please keep in mind that nutrition is highly individual, what works for the majority may not work for you and vice versa. 
3. When considering exercise/sport nutrition, the two important factors are: glycogen stores (when you last ate) and exercise duration/intensity. Please keep these in mind when planning your meals and workouts. 
4. Foods are not inherently good or bad (unless you have an allergy). What matters is the amount of food and the frequency. Nutrition is a balancing act, and while there are seldom hard and fast rules, you generally want to consume a diverse range of foods (vegetables, fruit, wholegrains and proteins - plant or animal)

Do I Really Need To Eat During A Marathon?

Short answer: Yes. By eating during a marathon, you set yourself up for finishing strongly and recovering well.

Long answer: Have you ever tried driving a car without petrol or charging? Your body runs on fuel too, the difference is that we consume food rather than petroleum or electricity. As you run, your body metabolises energy from the food that you eat, as well as using glycogen that your body stores in your liver and skeletal muscle (500-600g total), which is depleted after roughly 90-120 minutes of running.

It’s important to plan and trial your nutrition strategy when you begin your training to give your body ample time to adjust to processing food while exercising. This is because blood flow is directed away from your digestive system to your legs, making digestion slower. However, your gut is fascinating and can be trained to adapt to different foods, even under duress. If you’re a little nervous, start with small amounts on small runs before building up distance and quantity. 

What exactly to eat during a run and when can look different for everyone depending on what works best for you (your metabolism, running intensity, eating habits, digestion, etc.) 

What If I Find It Hard To Eat While Running?

Difficulty eating when running is certainly something that can be trained, or improved on depending on what exactly you’re finding difficult. If it’s the actual process of eating, such as chewing, breathing and swallowing, change the type of food to minimise crumbs or chewing. You don’t need to have a meal or a whole piece of food, you can take a really small bite of an energy bar or have a single lolly to provide some sustenance, which, when repeated consistently, can help your digestive system gradually adapt to the process of digestion during exercise. Start by eating while walking, then gradually build up your pace. If this is still tricky, there is nothing wrong with walking for 100m out of 42km to get some sustenance. 

If it’s a matter of getting a stitch or experiencing digestive distress, maybe you need to reduce your pace ever so slightly after eating. Products specifically made for gentle digestion, like Maurten energy gels, use hydrogel-based carbohydrates which surround the carbs once they reach the stomach and allow movement through without causing digestive upset. The first person in history to run a sub-2-hour marathon was runner Eliud Kipchoge, who swears by Maurten. “I’d like to put it this way - Maurten is a game changer in sport”. Alternatively, Tailwind Nutrition is another gut-friendly endurance fuel made to replace sports drinks, gels or chews containing both electrolytes for hydration and sugars for energy, 

How Can I Plan My Marathon Nutrition?

When planning your marathon nutrition, it’s essential to:

1. Consider your general nutrition. Why? Because this is what is going to provide you with your daily energy requirements, impact your pre-exercise nutrition and contribute to your recovery. Aim to eat a diverse range of nutrient-dense carbohydrates, vegetables and protein, at the same time limiting discretionary foods. Check out the Australian Dietary Guidelines for more information.

2. If you’re just getting started, check out our blog on what to eat before exercising to get an introduction on what to eat and when. Knowing how your body functions during exercise is instrumental in knowing what foods you should or shouldn’t be consuming during a run. 

3. Know your route and look up the plan for the actual event day. If there are going to be particular energy gels supplied by the organiser or a sponsor, do you want to use their nutrition or would you prefer to choose your own energy gels? Will you be carrying a hydration pack, or will you rely on the hydration stations that can be prone to bottlenecks, spilling and disrupted pace, but take a literal weight off your shoulders?

4. Furthermore, what time is your event starting? If you only train in the late morning or afternoon, but your event starts at 6 am, then you will also need to train your stomach for the correct starting hour so your body can be ready on time. 

5. PRACTICE. Once you know what pace you can comfortably maintain, how much water to drink, how much and what types of food to eat beforehand and during, then do a dress rehearsal (not the full 42km, more like 30km max) to get the flow of how everything will work together on the day.

Finally, use the same food on event day as you did in your training. This is not just during your run, but also pre-run nutrition. If you’re travelling, make sure you have amenities to prepare your meal or even take a portion of your normal pre-workout meal with you. If you use a certain brand of gels when training, like Precision Fuel, Koda or Maple Movement, then that’s what you’re using on the day - don’t change the concentration, recipe or quantity! Doing so can not just throw your digestion out the window, but also your blood sugar levels, which impacts your intensity and endurance.

When Should I Eat During A Marathon?

Let’s look at some numbers for pre-fuelling and fueling during your training, which will ultimately become during your marathon:

• Pre-run: Make sure that you have a decent meal 3-1 hours before you begin running. This provides your base fuel so subsequent feeds are just to maintain a certain level of energy and avoid the dreaded empty feeling. 

• During your run: Aim to eat 30-60g of carbs in the first hour, then increase to 60-90g after 3 hours. Ideally, you would consume small amounts of your chosen fuel every 30-45 minutes to aid digestion, keep a constant supply of food and avoid hitting ‘the wall’. Instead of eating a whole energy bar, bite off small pieces every 10-20 minutes or take half an energy gel with water to space out your snacking and maintain your energy levels.
• Post-run: Aim to eat 20-30g of protein and 60-90g of carbohydrates to restore glycogen stores and rebuild damaged muscle fibres.

All of these quantities and times need to be practised so you know whether it’s right for you. When you consider these numbers, think about when your event actually starts. 

Should I Wake Up Earlier To Eat A Meal Before Running?

Not really. Compromising sleep affects how efficiently your body works and impacts your performance. Consider instead your nutrition for dinner the night before and how your fuel during the race can compensate for a small pre-run snack.
 

Source: Emanuel Ekström

Should I Carb-Load Before An Event?

Carb-loading is a strategy used by endurance athletes who are active at high intensity for more than 90 minutes, including marathons, triathlons, or cycling events. It can enhance endurance and reduce fatigue, but does not increase your speed.

If you haven’t tried or heard of carb-loading, the process starts usually 3 days before your event/activity when you decrease your training intensity (known as tapering) and at the same time, increase your intake of carbohydrates to 7-12g/kg body weight/day to maximise glycogen storage (usually an extra serving of pasta/bread/rice/potato/noodles/oats) 

• 3 days before your event: You can add a slightly higher portion of carbs to your diet. Prioritise complex carbohydrates here for sustained energy in the lead-up to race day 
• 1-2 days before your event: Add more carbohydrates and decrease fibre and fat (combine simple and complex carbs).
• The day of your event: Eat a high amount of carbohydrates 4-3 hours before the event is due to start (combination of complex and simple for sustained energy and limit potential gastrointestinal discomfort)

Having a large meal the night before an event isn’t quite enough and can also cause digestive upset. For the strategy to work, the intake needs to be consistent, and you have to reduce the intensity of your training in the lead-up to maximise glycogen storage. Just having a large pizza or pasta for dinner before your event in the morning can lead you feeling full, heavy, and/or bloated.

What does an extra serve of carbohydrates look like? Serving sizes on the back of packages are determined by manufacturers, whereas the Australian Dietary Guidelines (currently 2013) have standard serving sizes based on age, sex and activity level. Check your recommended serving sizes online or look at the dietary guideline PDF by Eat For Health, an Australian government health initiative.
 

What Should I Eat Before/After A Marathon?

Exactly what YOU should eat to prepare for a marathon may differ from someone else, but the rough guide of 30-90g of carbohydrates and 20-30g of protein is a good place to start. 

Always check the Nutrition Information Panel (NIP) for actual nutrient amounts, or search the ‘amount of protein/carbohydrate in 100g’ of your chosen food. 

Because 120g of chicken ≠ 120g of protein (it’s actually 20-25g), we’ve made a table of foods targeting 30g of carbohydrates and 20-30g of protein so you can begin planning your general nutrition, including pre- and post- workout meals, and yes- there are also foods which you can take with you on your run.

Target of 30g Carbohydrates (COH)

Target of 20-30g Protein

A table is useful for knowing numbers, but food is more than nutrients; it’s comfort, social and enjoyment. Rarely do people eat a bowl of ricotta or a single piece of fish as a meal, so we’ve also made up a few examples of how you can use this table for your meal planning. 

What Should I Eat During A Marathon?

What you should eat during a marathon comes down to what foods you like and how often you personally need to eat. 45 minutes to an hour is the usual window for a first feeding, but consider how much you ate before you started running, you may require more or less frequent fueling.

A 2025 study published in Food Research International on the effect of physical exercise on taste perception suggested that sweetness perception intensifies with exercise. For regularly active people, this can mean they are more sensitive to sweetness and could be less willing to eat sweet foods. This is one of the reasons why sports nutrition brands like Maurten are so popular, because they have no additional flavour and a neutral taste. 

If you prefer salty foods over sweet, then you might need to prepare some foods yourself because the sports nutrition industry prioritises sweet flavour profiles such as chocolate, citrus, berry and -that popular yet vague flavour- tropical. We recommend trying Maurten, Pure, and Tailwind for unflavoured, or neutral tasting nutrition products. 

Ideas For Foods For A Marathon

Exactly what foods to eat during a marathon depend on your own palate and dietary requirements. Rules of thumb:

• Nothing too dry or crumbly: You don’t want to inhale a crumb and have a coughing fit, which will impact your breathing rate and -you know- your ability to breathe. You also don’t want your food to fall apart in your hand as you’re running and leave a trail of crumbs.
• Have a variety of different foods: To meet your nutritional needs and keep the eating experience enjoyable (carbohydrates, salty and sweet). eg. bars with dried fruit and oats, jerky, bananas, gels, olives (pitted) or freeze-dried fruits
• Always have an emergency fuel: On the day, you might go faster than in training just because of the excitement of being there. While you might feel great, this can impact your long-term energy management, so to avoid the dreaded ‘wall’, pack more fuel than you need and have an emergency portion. Think about jelly beans, or another form of lolly that can give you a boost and hopefully avoid fatigue, or help you claw your way out of the pit of despair. 

My personal recommendations can be found in this energy gel and energy bar review featuring a small selection of some of Wildfire Sports & Trek’s most popular brands including Clif Bar, 226ERS and SiS (Science In Sport). We also did a review of GU Energy gels, so if you’re looking for a new flavour, be sure to check out our ratings! 

How Much Water Should I Drink During A Marathon?

On average, you may need to consume somewhere between 300-800ml/hr of fluid whilst running a marathon. However, depending on the temperature, humidity, how much you sweat and how you hydrated the day and hours beforehand, this amount may differ. 

Drink both water and electrolyte drinks (1:1, or 1: 2 electrolytes: water) to replenish your hydration levels, especially if it’s humid or warm.

Sweat rate (loss/hour) and sweat sodium concentration impact the amount of salts you need to consume to replenish your body. Unless you’ve been to a sport science clinic, you likely don’t know your sweat concentration, but if you have white salt crystals on your clothing or skin after running or sweat heavily, then you may need more electrolytes or salt tablets. Not replenishing sodium, or overconsuming water, can lead to uncommon but serious low blood sodium levels known as hyponatremia. Slower runners are most at risk of overconsuming fluids, so be sure to know how much fluid you need when running. 

To figure out how much hydration you lose and should then aim to replenish, weigh yourself without clothing immediately before you go for a run (ideally an hour), then weigh yourself again as soon as you get back (also without clothing). 

If you can, try not to drink water during this run. If that’s not possible, make sure that you know how much you drank. The difference between your pre-run weight and post-run weight, plus fluid consumed (in litres), is your sweat loss/hour

Eg. 70kg pre-run, 69.5kg post-run, drank 200ml (0.2L)

Weight loss = 0.5kg

0.5 + 0.2 = 0.7

= 700ml/hour, meaning you would need to drink 700ml of fluid per hour to avoid dehydration. Ideally, you would repeat this in different weather conditions to know your range. 

How To Recover Well After A Marathon?

• Walk for 10-15 minutes to cool down and avoid blood and lactic acid pooling in your legs
• Have a snack to begin replenishing glycogen stores (my favourite post-race treat was a choccy milk, but a smoothie or recovery drink by Tailwind, SIS, Pure, or Pillar is a great option. Alternatively, see our tables above for targeting particular nutrients). See more about post-exercise nutrition in our blog on What to Eat Before Running
• Drink water (not alcohol as this can dehydrate you, save it for celebrating later if you wish), aim to consume 150% of fluids lost during the run over a 2-4 hour period (ideally with foods containing sodium to help retain fluids)
• Stay warm/seek shade. If the day is cold, try to get out of your sweaty clothes quickly and rug up; if it’s hot, find some shade to lower your core body temperature and cool down
• Congratulate yourself and take some time to reflect on what you achieved
• Stretch! If you have some sore limbs in particular, check out our tips for Post-Workout Massage to relieve tension, gain flexibility and relax
• Get a good sleep (7-9 hours) to give your body time to recover
• After 24 hours of resting, do some gentle walking to increase blood flow but not put any strain on tendons or muscles which might be a little sore
• Take 1-2 weeks off running to give your muscles time to recover properly

Regardless of whether you’re running your first or 101st marathon, make sure that you’re nutritionally prepared to give it your best and recover well. 

If you have any questions about our extensive range of sports nutrition options, come into Wildfire Sports & Trek at our Brisbane store to chat with our friendly staff, or contact us through our website.  

About The Author

Rachel Williamson - Nutrition Expert, Adventurer & Running Enthusiast 

Rachel has a Bachelor of Food and Nutrition Science (honours), and a passion for bread, whole foods and getting creative in the kitchen. Rachel traded cycling for running after a back injury and is now focussing on building up her fitness to run a marathon. Whilst the bread is proving, she's either out running, or spending time with her Kelpie, Tilly.