What to eat for a Trail Run
Written By: SportsShoes
Fuelling our running comes down to a simple equation. This being that running demands energy. It follows that the right energy source, combined with an effective fuelling strategy, equals optimised performance. Which can mean the difference between a personal best and the dreaded “runner’s bonk.” That’s all the more important for trail runners, as no one wants to hit the wall miles from home in a remote area.
While there’s no one-size-fits-all strategy, following the key rules below can help optimise your nutrition to keep you running the trails harder, and for longer.
- WHY A FUELLING STRATEGY IS IMPORTANT
- 24 HOURS BEFORE YOUR RUN
- 2 HOURS BEFORE YOUR RUN
- ON THE RUN
- AFTER YOUR RUN
- THE FINAL TAKEAWAY
1. WHY A FUELLING STRATEGY IS IMPORTANT
When we run, we use two primary sources for energy: carbohydrates stored in the muscles as glycogen, and stored fat. Put simply, the body prefers to burn glycogen, but we only have a limited supply that can be used for running. When those supplies run out (usually after around 90 minutes of running at effort for most people), the body turns to stored fat as fuel. For those not adapted to fat burning, that can mean a significant slowdown in performance, leading to fatigue and exhaustion. Studies have found that glycogen is a major limiting factor in athletic performance.
The upshot of this? It’s important to have a fuelling strategy whereby we take on sufficient carbohydrates to convert into fuel and allow the body to perform at its best.
2. 24 HOURS BEFORE YOUR RUN
First off, ascertain the demands of your upcoming run. Are you planning short and easy or long, fast and hard? Your priority is to ensure that you’ll have sufficient glycogen reserves for the next day’s running. For easy runs, you can fuel as normal the day before. For harder and longer runs, you should increase your carb intake with carb rich meals during the 24 hour period before your run.
Don’t Overload the Digestive System
If there’s one thing we would all choose to avoid on a long run, it would be the dreaded “runner’s trots.” The gastrointestinal upset caused by running can be exacerbated by overloading the digestive system - and carb loading by ploughing through a heavy meal the night before can do exactly that. Instead, continuously top up carbohydrates with a series of carb-rich meals over the preceding 24 hours.
Avoid GI Irritants
It follows on from this to avoid anything that might trigger a digestive upset or result in discomfort the day before you run. That means opting for foods that are easy to digest and avoiding very spicy or fatty foods.
3. 2 HOURS BEFORE YOUR RUN
Dependent on the nutritional demands of your run, the right snack in the hours beforehand can help stave off premature fatigue and regulate blood sugar levels. Here, you’re looking to boost energy without upsetting your stomach.
Easy Run Days
For easy runs of 30 minutes or less, you generally don’t need to worry about fuelling up and it’s fine to skip a pre-run snack. If you’re running for longer or at a higher intensity (but under 90 minutes) a small snack before you run, such as a banana or small bowl of oatmeal, can give you an energy boost and stave off hunger and fatigue towards the end of your session.
Hard Run Days
Don’t run on an empty tank. If it’s your long run day and you’re going to be running for over 90 minutes, have a more substantial snack within the 2 hours before your run. Snacks with low to medium GI foods work better here for a slow energy release. For example, whole grain toast with a banana and peanut butter, or a slice of malt loaf or yoghurt and granola.
How close to my run should I eat?
There’s no definitive answer to this. Some runners can tolerate food up to 30 minutes before their run, and for others it’s a digestive disaster. Finding your nutritional sweet spot can be trial and error, so make sure to experiment with this in your long runs until you find what works for you – but always stay within a timeframe of 30-120 minutes before running.
What should I eat?
It’s even more important here to avoid triggers that lead to digestive upset. Spicy, fatty and high fibre foods that are difficult to digest are an absolute no-no. Instead look for high carb, low fat and low fibre options, and particularly avoid excessive fruits or grains. An extra tip for morning runners: adding a small amount of protein can help stave off hunger pangs.
4. ON THE RUN
Your glycogen reserves last between 60 and 90 minutes. After this you’ll need ongoing fuel to help restore depleted stores or you’re heading straight for fatigue and a runner’s bonk. For that reason, mastering fuelling on the run is super-important to keep glycogen levels topped up, so that you don’t hit the wall. Your priority here is getting a fast energy boost to help you maintain pace and performance.
Fuelling on the run needs to be ultra disciplined and consistent. Know your numbers – the average runner can digest between 150 and 300 calories per hour and will burn between 600 and 1000. The idea is to take on just enough calories to maintain performance. This translates to an intake of around 60-90 grams of carbohydrates per hour.
Make sure to start fuelling relatively early – the longer we run, the more our digestion slows or even stops - and you should look to take on fuel no later than 45 minutes into your run. Follow this with around 100 calories every 20 to 30 minutes thereafter.
Sources of Energy
You’re looking for a fast energy source that can be easily absorbed and provides immediate availability of energy. Running nutrition products are designed to deliver that fast energy boost in an easily digestible form. Most contain a combination of two carbohydrate sources - Maltodextrin and Fructose which allows for better delivery, tolerance, absorption - plus, studies find they have a better performance effect than a single carbohydrate form.
Energy Gels & Chews – These are a popular method of fuelling on the run, usually containing around 100 calories each. They are designed to be easily swallowed or chewed, aid fast absorption, and being energy dense, allow you to easily ingest the carbohydrates you need to get a fast energy release. Some also contain electrolytes, caffeine and amino acids. The downside is that they can sometimes cause GI issues in some runners who struggle to tolerate them.
Sports Drinks – Designed to hydrate, replace lost electrolytes and deliver a carbohydrate boost, sports drinks are fast, easy way to refuel. However, it’s also harder to monitor your calorie and nutritional intake, and depending on the runner may not sit in the stomach as easily, causing bloating. Look for a carb concentration of 6-8% for the most efficient absorption and performance effect.
For advice on how to make your own homemade sports drink in three simple steps, go here!
If you’re running very long distances, you can potentially look at fuelling with solid food. The upside – this tastes better, which can be a bonus if you’re starting to feel nauseous. Solids are difficult to digest at a moderate to fast pace but some runners can tolerate them at slower paces. On the downside, solid food sources can be bulky to carry and you’re likely to end up ingesting fibre and inadvertently cause digestive upset. They’re also not optimised for fast absorption like nutrition products. Try peanut butter and jam sandwiches, rice cakes or bananas. Alternatively for an ultra-fast energy boost at a higher intensity pace, Jelly Babies and Wine Gums are still a favourite for many runners.
No runner is the same, and it can take time and patience to determine what works for you. Make sure to give your body time to adapt to new fuelling techniques and actively train your gut to take on fuel on the run.
5. AFTER YOUR RUN
The key here is recovery and the “3 Rs” are vital: Recover, Restore and Replenish. Your two primary nutritional goals are a) to kickstart the body’s repair process and b) to replenish depleted glycogen stores in time for your next run.
Maximise the recovery process by taking on protein and carbohydrates within 30 minutes of finishing your run - at a ratio of 3:1 carbs to protein. Bear in mind that faster-releasing higher glycaemic index foods will replenish glycogen stores more quickly, for example white bread or sugary cereals.
Example recovery snacks:
- Chocolate milk
- Banana with peanut butter
- Cottage Cheese on toast
- Fruit smoothie with a scoop of protein powder
6. THE FINAL TAKEAWAY
- The right fuelling strategy is unique to you and what works for one runner might not work for you.
- Make sure to experiment with different energy sources and strategies until you’ve determined what works best for you.
- Practice: Allow time for your body and gut to adapt to new fuelling strategies
- Always take in extra calories on runs lasting longer than 90 minutes
- Keep a training and nutrition log to help you monitor what does and doesn’t work. Making sure to include the days you felt great, and the days you felt sluggish, to help you nail down the strategies that work for you.
Find out more about off-road running by visiting our trail running hub and make sure you've got all the running kit you need for your next adventure.
Related post: A Beginner's Guide to Trail Running | The Trail Hub | SportsShoes.com