What to Eat Before a Long Run

As runners, we often question what to eat before a long run. Fuelling effectively is important in order to maximise performance and to avoid hitting the dreaded wall. Even for beginners who are running smaller distances, this is important - but as your distances increase, both the energy required, and the impact on your body get more significant, so an effective fuelling strategy becomes more and more of a necessity.

We spend a fair amount of time studying the latest nutrition research and speaking to runners about what works for them.

This post will share some of that experience with you - breaking down the best pre-run foods for fuelling before a long run, talking about some of the science around why those foods are so helpful.

But first, how long before a run should you eat?

When Should I Eat Before a Run?

Before a long run, your body needs adequate fuel stores, but you also need to avoid digestive discomfort that could derail your performance (or end it before it even starts!). Getting this balance right is helpful for both feeling good during your run and for achieving your best possible time.

While metabolism does vary from person to person and there will never be a one-size-fits-all timeframe, you should ideally have your main pre-run meal 3-4 hours before starting your run, with a smaller snack 1-2 hours beforehand if needed.

This allows your body time to digest and absorb the nutrients whilst ensuring your glycogen stores are topped up and ready to fuel your efforts. Eating too close to your run can lead to GI discomfort, whilst eating too far in advance may leave you running on empty.

What Nutrients Do I Need Before a Run?

Now that we’ve covered the timing, the next question is - what are the best foods to eat before a long run?

The key to successful pre-run fuelling lies in understanding what your body actually needs to continue performing well during extended periods of running. Decades of sports science research, combined with real-world testing by elite and recreational runners alike, has given us a pretty clear picture.

So let’s jump into the key points you need to know:

Carbohydrates are absolutely essential for pre-run nutrition. These are your body's preferred fuel source during any type of exercise, and unlike fat stores (which are more plentiful but also less efficient to use during exercise), your carbohydrate stores are limited. Your muscles and liver can store around 400-600g of carbohydrate as glycogen, which can be drained in as little as 60-90 minutes if running at a high intensity.

For runs lasting longer than 90 mins, you'll need to both start running with your glycogen stores as full as possible, and continue to replenish them with easy to digest, natural carbs as you run. For long runs and races, this also means consuming carb-rich foods in the days leading up to your long run, not just immediately before.

The type of carbohydrate makes a difference too. You'll want to focus on easily digestible options that won't cause stomach upset. Simple carbohydrates are generally better tolerated close to run time, whilst complex carbs work well in meals eaten several hours beforehand.

Hydration is just as crucial. You should start your run well-hydrated, which means drinking consistently in the 24 hours before your long run, not just 20 minutes before!! At the same time, do your best to avoid overdrinking immediately before running as this can easily lead to discomfort and frequent toilet stops.

Electrolytes are also important and if you’re lacking sodium as well as potassium, magnesium, calcium and chloride, your body will feel it. Starting a run with adequate electrolytes such as sodium and magnesium helps maintain fluid balance and can delay the onset of muscle cramps. So make sure you aren’t depleted of electrolytes before you even start a run, and continue taking them during your run. Consider how many electrolytes your body may need per hour, especially if you're a heavy sweater or running in hot conditions. A ballpark is 400-500mg of sodium per hour, 200mg potassium, 60mg magnesium and 60mg calcium, although some people may need upwards of 1000mg sodium per hour.

Protein also plays a supporting role in pre-run nutrition. While it's not a primary fuel source during running, and is more important after running to help rebuild muscle, a moderate amount can help maintain blood sugar levels and may reduce muscle breakdown during very long efforts. Do keep in mind though, that too much protein before a run can be problematic as it takes more energy to digest, and uses up water potentially causing dehydration and GI issues.

The Best Foods to Eat Before a Long Run

So what does all this nutrition science translate to in terms of actual food choices? The best pre-run foods are those that provide readily available energy whilst being gentle on your digestive system.

For your main meal 3-4 hours before running, focus on familiar foods that you know agree with you. This isn't the time to experiment with new recipes, new brands or exotic ingredients. Some excellent options include:

Porridge with banana and honey for a good balance of simple and complex carbohydrates.
Toast with peanut butter and jam provides easily digestible carbs, a quick energy boost, and smaller amounts of protein and fat.
Pasta with a simple tomato sauce is an easy way to get carbs with some additional electrolytes.
Rice with chicken and vegetables provides carbs, lean protein, and essential nutrients, but may be more filling than the other examples listed here and is best eaten earlier.

For a smaller snack 1-2 hours before your run, simpler is usually better:

A banana with a small amount of peanut butter - bananas contain easily digestible carbs and potassium.
A slice of white toast with honey or jam - white bread is more easy to digest than wholemeal, and the honey or jam provides quick energy.
Maple syrup gels - if solid food doesn't appeal or you're feeling nervous, liquid calories can be easier to tolerate.

Foods to Avoid Before Running

Just as important as knowing what to eat before running is understanding what foods could potentially sabotage your run. Certain foods are quite risky to eat before running and may even actively work against you.

For example:

High-fibre foods should be avoided in the hours immediately before running. While fibre is important for overall health, it can cause bloating, gas, and even urgent bathroom stops during your run.

High-fat foods take considerable energy to digest and can make you feel sluggish. Avoid full English breakfasts, pastries, or anything deep-fried before running.

Too much protein can be problematic close to run time. Large steaks, protein shakes, or multiple eggs might work fine 4+ hours before running, but can cause digestive issues if consumed closer to your start time. If protein is something you want to eat before running, consider a natural vegan source that is easier to digest.

Anything unfamiliar is risky before a long run. New foods, different brands, or exotic cuisines can cause unexpected reactions when your body is under the stress of prolonged exercise.

Excessive caffeine can be problematic for some runners, potentially causing jitters, stomach upset, or urgent bathroom needs. If you normally have caffeine, stick to your usual amount, but don't dramatically increase it on race day. Our maple coffee gels have the perfect amount of caffeine required to avoid GI discomfort - but even with these, you should stick to the instructions and avoid taking too many in a short time.

Individual Experimentation is Key

Whilst these guidelines provide a solid foundation based on the latest research and experiences shared with us by runners, everyone is different. What works brilliantly for one person might cause issues for another. Some runners can tolerate almost anything with no issue, whilst others have very sensitive stomachs.

The key is to experiment during your training runs, not leaving it until race day. Try different foods, different timing, and different quantities to find what works best for your body.

Pay attention to how different foods affect your energy levels, stomach comfort, and overall performance. Keep a food and running diary if needed to track what works and what doesn't.

Building A Pre-Run Routine That Works

Successfully fuelling before long runs isn't just about the immediate pre-run meal - it's about developing a routine that supports your training over time.

In the days leading up to a long run, focus on eating well-balanced meals with adequate carbohydrates to keep your glycogen stores topped up. Read our guide to carb loading and put it into action, especially before races. Avoid making dramatic changes to your usual diet too close to an event.

Stay consistently hydrated, not just on run days but throughout your training week. This makes it much easier to start your long runs in an optimal state, and gives you more time to sweat before hydration becomes an issue.

Consider your sleep as part of your fuelling strategy too. Poor sleep can affect how your body processes food and directly impacts your appetite and energy levels.

Most importantly, practice your pre-run nutrition strategy regularly during training. The more familiar your routine becomes, the more confident you'll feel when it comes to race day or that important long training run.

Remember, good pre-run nutrition is just one piece of the puzzle. Combined with proper training, adequate recovery, and smart pacing, it will help you achieve your running goals whilst making the journey more enjoyable.

Staying Fuelled During a Run

This post is focused on fuelling before a run to support improved performance. However, to ensure you get the most out of each run and recover for the next one as efficiently as possible, you should also read our related post on what to eat after a run for recovery.

Optimising both will give you the best chance of success and of increasing your performance consistently over time.

Even when doing both effectively, you will need to continue fuelling whilst running too, especially on longer runs. The most efficient way to take on carbs while running is to use easily absorbed, high carb and natural food such as our maple syrup gels or maple coffee gels.

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