10 Types of Food That Make You Run Slower

Our bodies are incomprehensibly interdependent. Things like drinking water can change our mood and glow up our skin. Moving our bodies can lift our spirits and give us more energy. Sharing life with people in a tight-knit community can lift the physical repercussions of stress from your body and lower blood pressure. Even the food that we ingest can affect our physical abilities and performance. 

Our body’s systems don’t operate independently, so it is important to consider what you eat. What you ingest before training sessions or on race day can make your running performance either faster and stronger or slower and inefficient.

Below, we’ll look at how food impacts your performance, which foods make you run slower, what you should eat before and during your runs, and the best foods for post-run recovery.

Let’s dig in with 10 types of food that make you run slower!

How Food Can Impact Your Running Performance

Types of food that make you run slower

Food is fuel. As gasoline fuels cars, food powers your body. Adequate fuel will help your “engine” run like a well-oiled machine as you log your miles. Inefficient fuel causes you to “stall out” with slower run times and possible gastric issues. 

Consuming food takes energy – it doesn’t just sit in your stomach without impacting your system. Your body breaks this food down to either be used later (in which case, it gets stored) or immediately as an energy boost. Nutrient-dense, higher-calorie foods help fuel running performance, while unhealthy foods can stall your progress. 

Not fueling properly will cause your workouts to be marked by indigestion, heartburn, cramping, bloating, and feeling sluggish with low energy levels. Not only will this make running significantly less enjoyable, but it will slow down your pace.

It’s important, especially for long-distance runners, to take an inventory of what you’re eating and if it’s adequately fueling you. Running on an empty stomach will make for lethargic workouts and can lead to more injuries. Adequate, appropriate fueling will propel you further and faster on race day and keep your mind-body connection sharp. 

10 Foods That Will Slow You Down

We have compiled a list of ten types of food that can negatively impact your running pace and cause discomfort along the way. Each runner is different, so we encourage you to figure out what foods fuel you and which foods leave you with an empty tank. 

1. Fiber-Rich Foods

Because foods high in fiber take so long (and so much energy) to digest, you will want to avoid these before a workout. Some of these foods include beans, berries, and broccoli (easy to remember, the three B’s). You’ll also want to avoid dense leafy greens, lentils, and whole grains. The same is true for them. 

In moderation, these foods shouldn’t interfere with your shorter runs, but too much could leave you with digestive discomfort. Eating too much fiber before a workout may leave you with stomach cramps or feeling bloated.

Of course, fiber is absolutely essential for your diet. Rather fuel up on these high-fiber foods after your training runs.

2. Dairy

Although it is a source of many good nutrients, consuming dairy before a run isn’t a great idea. Having dairy before you tie up your running shoes could leave you with an upset stomach and indigestion. In fact, dairy slows the absorption of carbohydrates in your body. We don’t want this as carbs are a source of longer-lasting energy. This point is even more relevant if you have any degree of intolerance to dairy.

You know your tolerance, though, and everyone’s body reacts to foods differently. Milk negatively affects some runners, but not all. Know yourself, and treat your body accordingly. 

Milk and coffee for runners
Both milk and coffee can have a dramatic effect on your running performance

3. High-Sugar Drinks

Although common sense suggests that consuming sugar before a run could help prevent a low blood sugar crash, eating simple sugars creates other issues. In your body, sugars are processed quickly and won’t get you very far on long runs. 

Especially not on race day. 

Experiencing a sugar crash mid-run could leave you feeling fatigued and will slow your pace considerably. Sugary drinks can also contribute to dehydration, which is another extreme you want to avoid. 

Instead of gulping down simple sugars, consider eating carbohydrates like pasta and rice. Carbohydrates are like “jet fuel” for your muscles and will supply your body with longer-lasting energy.

4. High-Fat Foods

Fat is not the enemy, but some fats may leave you feeling full. No one wants to run feeling like they have a brick in their belly, right? High-fat foods, especially fried foods, are a no-go before your training runs, especially on race day. If you can keep them to a minimum in your diet in general, you’ll be all the better for it. 

High-fat foods will leave you feeling sleepy and sluggish. They sit in the bottom of your stomach like a rock. Fat is turned into energy much less effectively than carbohydrates, so any energizing effects you may get are short-lived. 

Although you should avoid pre-training meals such as fast food or processed meats and cheese, healthy monounsaturated fats like those found in avocado and nuts are fine. 

5. Spicy Food

Spicy food may boost your metabolism but can also cause gastrointestinal distress, bloating, and heartburn when running. Although the spicy food itself may not slow you down, discomfort and heartburn will. This is the way to go if you feel like running with a fire in your stomach. You don’t want to? Yeah, we thought not!

6. Low-Calorie Foods

Low-calorie foods may make you feel full just after eating but will deplete your energy stores shortly after beginning your workout. Just like a car cannot run without fuel, neither can an athlete run without more substantial food fuel. 

7. Large Meals

Eating a large meal before you run can leave you feeling like you need a nap. Imagine eating a couple of Big Macs with a side of fries on the way to the gym! Your stomach feeling heavy will absolutely slow you down and make your runs a lot less enjoyable. Wait three to four hours after a big meal to do any high-intensity activity.

Fast food is not good for runners
Not a good idea!

8. Raw Fruits/Vegetables (specifically for race day)

As with all of the other items on this list, you know your body best. So if eating raw fruits and vegetables works for you, great! But for most, eating raw fruits and vegetables before stepping up to the starting line can cause all sorts of problems for your gut. 

Cooked fruits and vegetables may work better for you in small amounts. Stone fruits, blueberries, bananas, and rainbow vegetables are good go-to’s if you wish to eat fruits and veggies before your training runs.

9. Coffee

Although coffee can increase your heart rate pre-workout, it is not a sustainable fuel source. Hundreds of studies have suggested that athletes may perform at a higher level when they don’t gulp down a cup of joe. There are differing viewpoints on this, so listen to your body’s cues on whether or not coffee helps or hurts and follow accordingly. 

10. Too Much Water

Although it may seem counterintuitive, drinking too much water can also slow you down when running. Beyond feeling bloated, heavy, full, and uncomfortable, hyponatremia happens when someone ingests so much fluid that their body can’t get rid of the surplus (via sweating or urination). 

This causes the body’s water levels to rise and dilute the sodium levels. If left untreated, this condition can cause damage to the brain. When running, drink when your body is telling you it’s thirsty – and don’t overdo it. Take small sips.

Power-Packed Snacks

Instead of turning to the foods we’ve listed above, we suggest some of these snacks to fuel you up before your training run or race day. Above all, do not neglect fueling your body. A 100-300 calorie snack is a good way to give you the energy you need without bogging you down. 

Studies have shown that carbohydrates that can be easily consumed and digested about an hour before working out allow runners more longevity. 

  1. Bananas – great for potassium to prevent cramping and electrolyte replenishment.
  2. Healthy fats (avocado, oils) 
  3. Hard-boiled egg and juice 
  4. Pretzels and peanut butter 
  5. Dried fruit 
  6. Rice cake with hummus 
  7. Small bagel with peanut butter
  8. Pasta – (without the rich, dairy-based sauce)
  9. Oats 
  10. Lean Proteins (fish, poultry, tofu, lentils)

What to Eat During Your Long Runs

While logging those longer distances, you will inevitably need to fuel up mid-run. Dozens of sports gels and drinks are easily digestible and can provide that little boost to help you get through the barrier or pain cave. 

They can also give you the extra carbs and sugars to push the pace further. Ensure you “practice” eating gels or drinks before race day because they take some getting used to and can cause unpleasant stomach issues if your stomach isn’t used to them. 

Other easy mid-run snack ideas are peanut butter packets, dried fruit, apple sauce, bananas, or mashed potatoes. Higher carbohydrate snacks you can bring along on long runs include pretzels or granola bars. Try a few out during your training runs to know what works best for you come race day! 

See more: What is the best food to increase stamina for running long distance?

Fuel Up Post-Run

It’s also important to give your muscles fuel post-run. This helps prevent cramping and injuries, increases the rate of recovery, and fortifies your fitness goals. 

Chocolate Milk

Chocolate milk happens to be an incredible post-run drink. And let’s be honest – who doesn’t want to drink chocolate milk after burning crazy calories? It’s packed with high-quality protein and easily-digestible carbohydrates. It’s perfect for muscle building, recovery, and energy refueling. 

Whey Protein Drink

Whey protein powder stands high above alternative proteins because it contains the nine essential amino acids. These amino acids and protein kick-start the muscle-rebuilding process in your body. 

Grilled Chicken and Roasted Vegetables

Grilled chicken is a lean protein, and cooking vegetables instead of eating them raw will make them easier for your body to digest. Mushrooms, zucchini, and asparagus are great vegetables to choose from. 

To add some extra carbohydrates, add a serving of pasta, rice, or potato. And if you’d like some healthy fats, pop some avocado on the plate too. This is a great meal for recovery. 

Loaded Oatmeal 

Oatmeal, on its own, is a source of high-quality carbohydrates and soluble fiber (called beta-glucan). You can load it up with extra ingredients for extra calories, proteins, and flavor. 

Some of our favorites are chia seeds, strawberry slices, a smear of peanut butter, blueberries, or dark chocolate chips. When decorating your oatmeal with extra caloric goodies, less is not more. The more, the merrier!

Our Verdict: Eat Well to Run Well

The food you ingest should help you get closer to your running goals. Eating the right food in the right quantities will maximize your performance and help guard your body against injuries and keep your mind sharp during exercise. 

Next time you’re restocking your pantry at the grocery store, think about these go and no-go foods and how they can help you accomplish your race day dreams!

Further reading: see our guides to the best minerals and vitamins for runners, as well as the best supplements for running.

Author Profile

Thalia Oosthuizen

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Thalia started running during the the pandemic as a way of getting out of the house. The running bug bit, and now much of her life revolves around everything to do with running - videos, podcasts, studies, books, articles, and interviews. She's also done several courses on running nutrition and mechanics to aid in her training and advising others.
Thalia Oosthuizen

Revel SPorts Contributor

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