One of the most frequent questions I receive from athletes is about pre-run snacks. Trends of fasted running, fears of GI distress, and early morning alarms all compel runners to sometimes skip a pre-run snack.
Why Should You Eat a Pre-Run Snack?
No matter what time of day you run, a pre-run snack enhances performance by literally putting fuel in your tank. As a 2018 meta-analysis in the Scandanavian Journal of Medicine and Science in Sports points out (and most runners can attest to based on real life experience), pre-exercise eating improves aerobic performance.
A pre-run snack is especially important if you plan on running a quality session (speed work, fartlek, hills, tempo, long run, etc). Whenever you run above aerobic threshold (approximately marathon pace for a majority of runners), you burn a higher percentage of calories from carbohydrates. These energy demands require easily available energy; skipping a pre-run snack can hinder your performance and therefore the benefits of the workout. Even if you prefer to run your easy runs fasted, you want to ensure you at least consume liquid calories before a hard workout.
If you are running before breakfast, a pre-run snack serves the purpose of topping off your body’s carbohydrate stores. The overnight fast of sleeping can deplete up to half of your glycogen (stored carbohydrate), so a snack gives a boost of mental and physical energy for your run. The carbs from your snack will prevent any bonking or sluggishness on your run. You want to find a small snack that you can eat right before you start running; sports nutrition products such as bars, chews, or waffles can be highly beneficial, since they are made to be easily digested.
More research indicates that within-day energy availability affects athletic performance. If you are a morning runner or running in the evening after work (several hours after your last meal), a snack will fill in a window of otherwise low energy availability.
You may hear some runners tout the benefits of fasted running for increased fat burning and therefore improved endurance. While there are always outliers for whom odd approaches work, fasted running will not help a majority of runners. When you run in a fasted state, your body searches for alternative fuel sources. It will burn fat – but it will also break down your muscles for protein, as demonstrated in a 2011 study in Strength and Conditioning Journal.
What If You are Prone to GI Distress?
The most important thing to remember is that your stomach is a muscle; you can train it. Gut training is highly effective for runners. Essentially, if eating before a run causes GI upset, you teach your stomach to handle it. First, you gradually introduce small amounts of food (think half of a banana) and eat that before your runs for a week or two. After an adaptation phase, then slowly increase the amount and allow time for your body to adapt.
Not only is hydration vital for running; it can prevent GI upset. Even minor dehydration will cause your body to pull water from your gut into your bloodstream. Less water in your gut means poorer digestion, which will increase the chance of stomach upset. Be sure to drink a glass of water or electrolyte drink with your pre-run snack.
Pre-Run Snack Ideas
Ideally, you want to select easily digestible foods (not high in fiber) that are high in carbohydrates. You may choose to add a bit of fat or protein for satiety, but both fat and protein are slower to digest, so test your option on a shorter run first.
- Graham crackers, plain or with nut butter
- Banana, plain or with nut butter
- Bar, such as ClifBar
- Toast or half a bagel with honey or jam
- Roasted/boiled red potato with salt
- Sweet potato with honey
- Juice or sports drink
- Honey Stinger waffles
All of these options contain easily digestible carbohydrates and are relatively small in volume. You will notice that none of these foods are high in fiber. Some of the options add fat, which can help you stay fuller for longer and provide some energy (you burn fat and carbs while running).
What NOT to Eat Before a Run
While everyone is different, I recommend avoiding potentially irritating foods or foods that are slow to digest. Even if you are not sensitive to these, they may leave your stomach feeling heavy or upset on a run:
- Dairy products: milk, cream, cheese, yogurt
- High-fiber vegetables, especially broccoli, cauliflower, kale
Ultimately, though, every runner is different. Maybe you can have a green smoothie before a run and be fine! Alternatively, you may find that the normal options such as peanut butter do not sit well with you. Use trial and error and consider what you are eating and when you are eating when finding a pre-run snack that works for you.
When Should You Eat Your Pre-Run Snack?
Individual factors must be considered in the timing of a pre-run snack:
- Time of day: early morning run or did you just eat lunch a couple of hours ago?
- Digestion: Is your stomach sensitive?
- Duration of run: Longer runs require more food before, which can mean more time to digest.
Ideally, you want to allow 30-60 minutes for a smaller snack to digest, such as a banana or dried fruit. Runners with stomaches of steel can usually run less than an hour after eating even a sizeable snack. For larger snacks before long runs, or if you have a sensitive stomach, allow 1-2 hours to digest. If you need more than 2 hours for a pre-run snack, consider trying other options to see if they digest better – especially if you are a morning runner.
Use your hunger as a cue for running after meals. If you are feeling ravenous already and have a run over 30-45 minutes or a harder workout planned, have a small snack (such as a banana or dried fruit) – you do not want to be running on empty. If you just ate a full meal a couple hours ago and do not feel hunger, then you do not need a pre-run snack – your meal will sustain you through the run.
A Little Extra Boost
Coffee: Caffeine offers numerous benefits for runners, including improved athletic performance, extra alertness, and help in emptying the bowels before a run (which we all know, is as essential as a pre-run snack!). If you are not a regular coffee drinker, begin with about half of a cup before a shorter run to see how your body responds.
Beet Juice: I have used beet juice before some hard workouts, in addition to a banana. It provides a few extra carbs and some research indicates that it improves athletic performance. I find it a bit pricy to use for everyday runs, but I have and will use it before goal races and peak workouts.
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What’s your go-to pre-run snack?
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