Discover exactly what to eat before running and unlock sustained energy with our ultimate pre-run nutrition guide. Because your stomach shouldn't outrun your legs.

What To Eat Before Running: Your Ultimate Pre-Run Nutrition Guide 

Whether you’re new to running or a frequent participant in ultras, marathons or parkruns, the question of diet always comes up. I’m here to answer common questions about nutrition and running, including what foods to avoid, suggestions for what you could add to your diet and whether you should focus on pre or post-workout nutrition. 
 

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

1. I am not a registered dietician. 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 food behaviours or idiosyncrasies, etc., before making changes to your diet or exercise regime. Consult your GP or a dietician 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 nutrition, the two important factors are: glycogen stores (when you last ate), and exercise duration/intensity (this will all be explained further down). 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)

Nutrition Terminology Explained

Complex carbohydrates: Brown rice, oats, wholewheat pasta and bread, potatoes (with skin), legumes, pulses, fruits and vegetables

Simple carbohydrates: White rice, plain pasta, white bread (milk, brioche, etc.), soft drinks, lollies/sweets, syrups, honey, chocolate, sugary cereals, chips and sweet baked goods 

Discretionary foods: Food and drinks that are not considered essential for providing daily nutritional needs. These foods are often high in saturated fat, added sugars and/or salt, with a high energy density, but low in fibre and nutrient density (chocolate, cake, biscuits, chips, soft drinks, sports drinks, and alcohol). For more information, go to eatforhealth.

Nutrient dense: May be high or low and refers to the amount of nutrients per calories (high nutrient dense foods examples: broccoli, salmon, fruit and quinoa, seeds; low nutrient dense food examples: lollies, soft drinks, cakes and biscuits)

Energy dense: May be high or low and refers to the amount of calories in a food (high energy dense foods: fast food, chips, and sweets; low energy dense foods: fruits, vegetables, soups, air-popped popcorn. 

Anabolic window: Anabolic state is when your body uses energy to build and repair tissues (usually muscle), compared to the catabolic state, where your body breaks down tissue for energy. The ‘window’ refers to the timing of obtaining nutrients (through eating food) to provide sufficient energy for repairing the tissues. Protein intake is the priority here.
 

Source: Abhishek Hajare

What Types Of Food Should I Eat Before A Run/Workout?

Right before going for a run, you should prioritise easily digestible foods that are high in carbohydrates and relatively low in fibre and fat (yes, this is one of those times it can be helpful to eat simple carbohydrates or discretionary foods).

Why should I eat foods high in carbs before a run?

Carbohydrates are broken down into individual sugars (think of glucose, galactose and fructose as the building blocks for the larger sugars sucrose, lactose and maltose). Glucose specifically is stored as glycogen to fuel muscles as a quick-access energy. This is the first energy source that is used for powering your legs, arms and core. 

When talking about carbohydrates, I don’t mean a bowl of pasta or a whole loaf of bread. Carbohydrates are starches and sugars which your body utilises for energy - fun fact, the sugar glucose is the primary energy used by your brain, so if you don’t consume enough, your brain gets fatigued. The flip side is that eating too many carbohydrates leads to your body storing that energy as fat. 

Is fibre good before a run?

Fibre is essential for regulating bowel movements, stabilising blood sugar, lowering cholesterol and aiding digestive health as well as heart health and can also improve mental health. Fibre can also increase water retention, which helps digestion, but when exercising can lead to stomach discomfort or bloating. Best to save fibre for after your workout or a few hours beforehand.

Should runners eat low-fat?

Though fat is one of two sources of energy that the body uses as fuel, it takes longer to break down compared to carbohydrates, making it less practical and reliable when your body is already working hard. When including fats, it’s always recommended to use healthy fats, not deep-fried foods, but avocados, nuts, olive oil, seeds and fish (salmon, sardines, trout, herring, anchovies, etc.)
 

What Foods To Avoid Before Exercise?

It’s best to avoid foods that are overly spicy, rich or high in caffeine, as this can increase the risk of indigestion, stomach issues and dehydration. 

Special note on caffeine: Food Standards Australia New Zealand (FSANZ), along with other food government bodies around the world, recommends a maximum of 400mg total caffeine consumption per day. Keep in mind that a single 30g shot of espresso contains ~63.6mg, so if you have a medium latte (generally 2 shots) with breakfast, you’ve already had 30% of your intake for the day. Energy gels often contain caffeine, as it can help with cognitive function, but the amount can range from 20-100mg per gel, so be sure to check the amount before pouring the contents down your throat and going for a run. 

Why does this matter if you’re not sensitive to caffeine? Caffeine stimulates the digestive system by increasing stomach acidity and accelerating colon contractions. A small amount can help digestion, but can lead to diarrhoea and then dehydration if consumed in excess. If in doubt, just stick to a single coffee and go for caffeine-free energy gels before your morning run. 

On spicy foods: Capsaicin can irritate your stomach, leading to digestive issues, indigestion or heartburn, however, if you eat spicy foods daily, then you may not be negatively affected. Listen to your body, and if in doubt, keep your first few runs after spice close to home.

Source: Prasanta Dutta

When Should I Eat Before A Run?

This largely depends on when you’re planning on running and when you last ate.

If you like to go for a short run (<30 minutes) first thing in the morning and you had a satisfying dinner the night before, you shouldn’t need any additional fuel for your body to function.

If you’re planning on running for 60 minutes or more, or exercising at a high intensity, then yes, you should eat 30-60 minutes before you plan on leaving. If you find that you’re a little flat, have a small snack before you head out the door for a glucose boost to avoid fatigue.

Generally speaking:

You want to have a balanced meal (containing complex carbohydrates, protein, fibre and healthy fats) 4 - 2 hours before exercising. Any longer than this and you’ll likely need a snack 30 minutes before you begin your exercise. 

Why wait 30 minutes after eating to exercise? It’s not essential or dangerous (like the myth of an increased risk of drowning if you get in the pool too early), it’s to avoid the discomfort of food moving to your stomach and reduce the risk of indigestion or food coming back up.

Source: Nature Zen

Can I Have A Smoothie Before A Workout?

Short answer: Sure! Some people prefer to have a smoothie over solid foods before an event.

Long answer: If you like to have a smoothie before working out, make sure that it’s at least 1 hour beforehand. It’s a lot of liquid, and depending on what ingredients you use, it can also be a lot of fibre, which, combined, can cause stomach upset.

The priority of smoothie ingredients changes depending on whether it’s before or after your workout. Pre-workout, you want to focus on easily digestible carbohydrates to give you energy that is easily accessible. Post-workout, you want to include protein and some carbohydrates for muscle repair and to replenish glycogen stores. 

Consider combining some of the following: banana, nut butters, oats, protein powders, milk, yoghurt, spinach, apple juice, coconut water, berries, pineapple, mango, avocado, dates, cinnamon and chia seeds. Personally, these are two smoothies that I like to make. 

Zing smoothie: (pre-workout)

60g Frozen spinach

½ Green apple

250ml Coconut water

1tsp Ginger (minced or a small chunk to taste)

½ Avocado

½ cup Frozen mango or pineapple

1tbsp Flaxseed or LSA meal (I sometimes swap out for chia seeds)

1 scoop protein powder

Combine all ingredients in a blender

Bliss smoothie: (post-workout)

100g Yoghurt

50g Blueberries (frozen/fresh)

1 Banana (fresh/frozen)

2 tsp Chia seeds

250ml Milk of choice

50g Rolled oats

1 tbsp Nut butter (optional)

1 scoop Protein powder

Combine all ingredients in a blender

Can I Run 5km On An Empty Stomach?

Short answer: Yes

Long answer: As long as you’ve eaten within the last 24 hours, you can run 5km on an empty stomach. The question of exercise during fasting makes the rounds on social media seemingly every year, and while most people claim that running on an empty stomach gives them more energy and helps them lose weight, others can experience fatigue, headaches and dizziness. Even the research is out on this one.

Nutrition is highly individual (yes, underlined and bold is essential here). If you experience these symptoms when running on an empty stomach, do yourself a favour and have a little something before heading out the door.

Is Pre-Exercise Nutrition Or Post-Exercise Nutrition More Important?

Short answer: Pre-exercise nutrition

Long answer: A lot of importance is placed on post-exercise nutrition if you go online, but general and pre-exercise nutrition are not to be ignored and indeed can actually be more important. 

Pre-exercise nutrition has been found to not only assist performance but can also aid recovery and adaptation, minimising muscle damage. Roughly 30 minutes before you begin your exercise, have a snack of carbohydrates to improve your performance by providing a glucose boost. If you include protein as well, you can remove the immediate need for post-exercise nutrition and focus solely on nutrition in general. This involves eating a balanced meal, not just a bowl of noodles with seasoning, including protein, fibre, healthy fats and complex carbohydrates 4-2 hours before you exercise.

Post-exercise nutrition is based around a timing strategy called the “anabolic window”; 30-60 minutes after a workout is thought to be the optimal period for replenishing glycogen stores and muscle protein synthesis. However, this window may actually extend to 5-6 hours, or become narrower depending on when you last ate, narrower if you last ate over 4 hours before working out and extended if you consumed carbohydrates and protein before exercise. 

While gym-fluencers may convince you that you need to hit post-workout protein hard, if you’ve had pre-workout protein (0.4-0.5g/kg of lean body mass, which for many of us is 20-40g of protein), it can eliminate the need for immediate post-exercise protein consumption. 

If you’re exercising in a “fasted state” (~4 hours after your last meal), then the importance of post-workout nutrition is increased. Include carbohydrates and protein in your pre-workout meal, and you don’t need to stress about the post-workout meal.

Pre-workout snack ideas

Discretionary foods can be useful in small doses for short term-fuelling. The high energy that they provide from simple sugars is absorbed quickly, helping you to bounce back from the wall you hit or prepare for short, high-intensity exercise. You don’t want to be having constant energy spikes, though, because the flip side of the spike is the crash- that drained, totally empty feeling where you have a choice between keeping your eyes open or using your limbs. 

Overall nutrition can help keep a steady baseline energy (remember to focus on wholegrains and fibre), then a snack pre-workout for an extra boost when needed. 

With this approach, you don’t need as much fuel as you might think. We’re talking about snacks! I know sprinters from cycling and track and field who have a normal breakfast first thing in the morning, then have a couple of snake lollies or jelly beans 15 minutes before their event, so they aren’t sitting on unused energy for hours beforehand, or affecting their performance because of digestion. 

Looking for some suggestions on what you can use for a boost?

Small snack ideas before a workout (if you’re doing an easy workout)

• Date/seed bars
• Banana/handful of berries/a single mango cheek
• Muesli bar
• Dried fruit and nuts (trail mix)
• Nut butters on fruit or crackers
• Small handful (<50g) of lollies
• Small handful of pretzel chips

Medium snack ideas before a workout: (30 minutes before exercising) 

• Toast with jam, peanut butter, banana or honey
• Porridge with fruit and nuts
• Muesli with yoghurt and fruit
• Small smoothie with protein and carbohydrates
• Dark fruit cake

Regardless of whether you’re running a marathon, heading to the gym, or playing in your local social team, make sure that you’re nutritionally prepared to give it your best! 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.  

Rachel has a Bachelor's in Food and Nutrition Science with a passion for bread, whole foods and getting creative in the kitchen. Rachel traded cycling for running after injury and is currently focusing on training for her first half-marathon. Whilst the bread is proofing, she’s either out running or spending time with her Kelpie, Tilly.