Foods to Avoid (And to Eat) Before You Go Running

Have you ever stopped in the middle of a run due to stomach cramps or an abrupt lack of energy? It may be due to the types of foods you’re eating in the hours before your run.  A food’s impact on your run varies with its nutritional composition and the time you choose to eat it, making it important that you be deliberate in deciding when and what to eat before running.

Timing is everything

The purpose of a pre-run meal is pretty straightforward: to stave off hunger once you hit the trails (or streets). It also helps keep your blood sugar levels from dropping – a common cause of lightheadedness and impaired concentration. Those symptoms are definitely not the building blocks of a successful run. Planning out your meals and snacks in the hours before your run will ensure that you won’t get hungry or feel depleted prematurely. If you’re planning to scarf down a full meal, budget at least two to three hours for optimal digestion. If you’re aiming for a small meal or snack, you should still give yourself at least 30 minutes to digest to avoid the “heavy” Thanksgiving dinner feeling once you’re on the move. 

Determine what to eat before running 

Firstly, it’s important to determine what type of run you’ll be doing. If you’re going for a jog or a low-intensity run, your body will be using fat as its main energy source. In this case, a small protein-heavy snack will do the job. You could even get away with doing a fasted run, which is when you don’t eat at all before you exercise. If you’ll be doing a more intense workout, such as sprints or training for a long-distance race, your body will be drawing on glycogen stores (carbs) for energy. Therefore, loading up on healthy carb sources beforehand is key. 

Perhaps you’ve seen foods identified as high or low “GI” foods. This refers to the glycemic index, which ranks carbohydrates on a scale of 0 to 100 based on how much they affect your blood sugar levels after consuming. Foods with a score of 55 or higher are considered high GI foods, meaning they are rapidly digested and absorbed. These are the foods you want to eat before a run. If you want to evaluate your diet according to this metric, the University of Sydney’s Glycemic Index tool lists thousands of food items and their associated GI level.

glycemic index infographic

Carbs are your body’s most productive and readily available fuel source because they require less oxygen to burn compared to fat and protein. One study found that carb-loading actually delayed the onset of fatigue during exercise by nearly 20% and improved people’s overall performance. Another study found that ingesting protein alongside carbs did nothing to improve people’s running time trials compared to eating carbs alone. Long story short: Always reach for carbs first when choosing what to eat before running, then pair them with protein and fat sources if you desire. This combination will help your body easily digest and absorb the fuel in a timely manner. 

Foods to avoid before running

no donuts

Now that you know which foods you should be eating and when you should consume your pre-run meals, it’s important to understand which foods to avoid before running. While some of the foods on this list are highly nutritious, they can stop you in your tracks during a run. Here are some foods to avoid when getting ready for your next trek.

1. High-fiber foods: These foods can be broken down into a few categories – animal sources (bacon, red meat), vegetables (broccoli, artichokes, onions), and fruits (apples, pears). Avoid these fibrous foods as much as you can due to the toll they can take on your digestive system during exercise.

2. Spicy foods: Spice can add tons of flavor to a meal, but it can also lead to heartburn and digestive issues. Save the hot sauce for after your run.

3. High-fat foods: Heavy sources of fat before a run are a total no-go. Especially with foods high in saturated fat (which includes most fast food, such as burgers), the fat will sit longer in your stomach, causing bloating and stomach pains during your run.

4. Most dairy products: The reason many people have issues digesting dairy is because of lactose. Bypass heavy cheeses and milk to avoid unnecessary setbacks.

5. Caffeine (possibly): If you’re an early-morning runner, chugging a caffeine-loaded drink like coffee or Red Bull might sound appealing before you hit the road, but you should proceed with caution. Studies have shown caffeine may enhance athletic performance, but it can also cause dizziness and heart palpitations. If you really need the sunrise boost, start with a small serving.

Foods to eat before running

This is the fun part: thinking about what you do get to eat. While we’ve established the importance of carbs before a run, that doesn’t mean you should dive headfirst into a bowl of pasta. When planning what to eat before running, instead aim for whole grains and whole foods. Here are a few ideas to get you started. 

1. Quick-cook oats with berries and nut butter: Not only is this a tasty twist on a classic peanut butter and jelly sandwich, but you’re also receiving fuel from two different types of carb sources. 

2. Two slices of whole-grain toast with poached eggs on top: This one-two punch of carbs and protein will keep you cruising. Scrambled or fried eggs on top are OK too, but you should avoid using too much oil. 

3. Whole-grain bread with peanut butter and a cut-up banana: Elvis was on to something when he made this food combo famous. Similar to oats with berries and nut butter, you’re getting a major carb dose with a bit of healthy fat on top.  

4. Low-fat yogurt with granola and berries: While you should stay away from most dairy items, low-fat yogurt is easier to digest and takes no time to put together with some carb-heavy toppings. 

5. Sweet potato with cinnamon: Sweet potatoes are a bomb of healthy carbs. Sprinkle cinnamon on top for extra anti-inflammatory benefits.   

Foods to take with you during longer runs

If you’re planning to run for at least 90 minutes, you better pack some snacks. Your body is limited to storing about 1,800 to 2,000 calories’ worth of energy at a time, which is equivalent to about 90 to 120 minutes of consecutive, strenuous running. If you’ve ever experienced hitting “the wall” during a run, that means you’ve burned through those energy reserves and depleted your muscle glycogen. Any carbs you take in during your run will help delay this process. Try out these snack ideas during your next long-distance run. 

1. Fig bars: The University of Sydney’s GI database gives fig bars a GI of 70. While they’re not the most nutritious choice, fig bars are extremely portable and will provide you with a quick dose of carbs and sugar. 

2. Energy bites/chews like Clif Bloks: Think of energy bites as a swift shot of fuel and electrolytes.

3. Raisins/grapes: Raisins are a fast, easy idea for a carb-y snack, and grapes will also give you a bit of hydration.  

At the end of the day, you know your body best. As you’re running, blood is flowing away from your stomach and straight to your hard-working muscles, making digestion a lower priority for your body. That’s why experimenting with different combinations of carbs and proteins before a run will help you understand what fuels your body best – and upsets your stomach the least. Before long, you’ll be a well-fueled machine on your way to your best run yet.