What Foods Should Runners Avoid?

Runners hope for ideal running conditions, but lack control over many important factors such as weather, sickness or even the lane they start in. However, runners are usually able to control their pre- and post-run nutrition. These dietary choices can significantly impact running both to enhance or detract from performance. In order to ensure the best possibility of success, athletes may want to know, what foods should runners avoid?

Specifically, in the hours before a run, athletes will want to avoid certain foods that can hinder performance due to unpleasant symptoms. Runners should avoid foods high in fat, fiber, sugar and non-nutritive sweeteners. They should also avoid new foods or food routines. 

A runner can generally include all foods as part of an overall balanced eating pattern. In general, limiting foods high in sugar, saturated fat and sodium can improve health outcomes and performance for runners.

Avoiding these foods helps prevent those unwanted trips to the porter potty, but only make up part of the nutrition equation. Continue reading for more information about the best diet choices for running.

What Foods Should a Runner Avoid Before a Race?

A runner will find that certain foods detract from performance when eaten too close to a run. While some foods more commonly cause issues with runners, others may uniquely trigger unwanted symptoms. Therefore, runners will want to stick to familiar foods and food routines. Experimenting with new food before a run can lead to surprising reactions that harm performance.

Foods High in Fat

Dietary fat plays an important role in an overall healthy diet and runners should look to include healthy fats in meals and snacks. However, fats also slows down digestion and leads to possible bloating, cramps and diarrhea when a runner eats large amounts in the hours before a run.

In the hours before a run, athletes should avoid fried foods, fatty cuts of meat, greasy pizza, pastries, cookies, ice-cream, etc.

Foods High in Fiber

Including fiber rich foods in the diet improves digestive health and helps prevent chronic disease. However, similar to dietary fat, high amounts of fiber close to a run will cause gut bloating and distress. Fiber tolerance depends on the individual and runners may find they can handle more or less fiber before a run.

High fiber foods include beans, many vegetables including cruciferous vegetables, beets, peels of fruit, high fiber cereals and bread, etc. 

Non-Nutritive Sweeteners

Nom-nutritive sweeteners include sugar alcohols and artificial sweeteners like Stevia, sucralose, aspartame and saccharine among many. Avoid foods labeled as sugar-free or light as they often contain these types of sweeteners. Non-nutritive sweeteners provide little to no energy and their poor digestibility cause diarrhea and stomach cramping.

Excessive Protein

Even too much protein can cause ill effects in a runner before a run. Similar to dietary fat, protein slows down digestion and can cause gut irritation. Pre-run meals and snacks should focus on carbohydrates with moderate amounts of protein. A protein shake, or meat focused meal may not make the best pre-run eating option.

Foods High in Sugar

The body releases insulin when carbohydrate and sugar enter the bloodstream. This insulin allows sugar to enter the cells for energy use. Eating foods high in sugar can lead to a rapid blood sugar rise and then crash instead of a more controlled blood sugar response with carbohydrates. While a runner may need a rapid sugar release during or right before an event, eating high sugar foods in the hours prior to a competition can lead to an energy slump during the run.

Save the candy, soda, chocolate and desserts for a special occasion.

Any Alcohol (it’s illegal for teenagers and harms performance)

First, teenagers shouldn’t consume any alcohol due to the associated harm of alcohol on brain, liver and overall health. On top of these negative health effects, alcohol causes nausea, dehydration, headaches and fatigue which all take away a runner’s ability to perform well.

Spicy Foods

The amount of spiciness tolerated before a run depends on the individual. These foods can irritate the digestive system and cause heartburn or diarrhea during a run.

Lactose (for individuals with lactose intolerance)

Studies do not support the claim that dairy foods increase mucus production. Dairy offers great pre-run and post-run benefits with quality protein, carbohydrates and important vitamins and minerals.

However, those with a diagnosed lactose intolerance will want to avoid dairy products with lactose. An intolerance to lactose means the body is unable to properly digest the lactose molecule. This poor digestion can lead to an upset stomach, diarrhea, bloating and vomiting.

What Foods Should a Runner Avoid in their Overall Diet?

Runners should not eliminate entire food groups or nutrients. This practice leads to nutrient deficiencies, unhealthy weight loss, preoccupation with food, disordered eating and other poor outcomes. A healthy eating pattern comes through looking to include more nutrient dense foods and following principles of variety and balance.

Nutrient dense foods offer a high number of nutrients per calorie whereas a nutrient empty food will provide less nutrients. Nutrient empty foods usually contain higher amounts of sugar, saturated fat and sodium and often go through more processing than other foods.

These lower nutrient foods can still find a place in a runner’s diet when consumed in moderation. However, runners will want to include more nutrient dense foods in order to meet their higher nutrient needs and to assist with necessary growth and repair. Eating too much of lower nutrient dense foods increases the risk for nutrient deficiencies, decreased performance and poor health. 

Nutrient-Rich Foods to Increase:

  • Whole grains
  • Vegetables
  • Fruit
  • Legumes (beans, lentils, soy)
  • Seafood
  • Eggs
  • Lean meat and poultry
  • Nuts
  • Seeds
  • Unsweetened dairy products

Nutrient-Empty Foods to Decrease:

  • Sweetened beverages
  • Refined grains
  • Ultra-processed foods
  • Fried foods
  • Desserts
  • Candy
  • Fatty cuts of meat
  • Processed meats (sausage, hot dogs, pepperoni, deli meats)
  • Flavored or sweetened dairy products

Should a Runner Avoid Carbohydrates?

As the main source of energy for the body, runners usually need to eat a diet higher, not lower, in carbohydrates. Avoiding carbohydrates will lead to early fatigue, lack of satisfaction with meals, and may affect growth and development of a teenager. 

Furthermore, high carbohydrate foods are some of the best sources of fiber. Whole grains, fruit, beans, nuts and seeds are all good sources of carbohydrate and fiber. Fiber promotes gut health, encourages good blood sugar control, aids with digestion and reduces risk of chronic disease like cancer, heart disease and diabetes.

A runner will want to make 45-65% of their calories come from carbohydrates. Preferably, these carbohydrates should come mostly from nutrient dense sources rather than higher sugar or refined choices. Meals and snacks before a run should heavily emphasize easy to digest carbohydrates with moderate protein. A combination of high carbohydrate and protein after a run will also help with glycogen and body tissue recovery.

Should a Runner Avoid Carbonated Drinks?

The athletic population widely acknowledges that soda does not lend many health or performance benefits. But, what about sparkling water, energy drinks or other carbonated beverages?

Carbonated beverages consumed too close to running may cause stomach bloating, upper digestive discomfort and distention due to the carbonation. Many sparkling beverages also contain non-nutritive sweeteners, which can exacerbate these negative symptoms. Energy drinks and soda contain high amounts of sugar and caffeine which negatively affect health and athletic performance.

In summary, an athlete can include unsweetened carbonated drinks in an overall healthy meal pattern but may want to hold off on these sparkling beverages in the hours before a run. However, an athlete will want to limit carbonated beverages high in sugar or caffeine to special occasions.

Does a Runner Need a Sports Drink?

Sports drinks contain carbohydrates and electrolytes to assist with hydration and energy. These drinks are helpful for runs lasting longer than sixty minutes or under conditions that cause excessive sweating. Athletes participating in shorter workouts can focus on meeting hydration needs through water. 

The higher sugar content of these drinks works well to replenish those energy stores during long runs. However, unnecessary intake of sports drinks during short workouts or as a daily beverage choice may cause excessive intake of calories and sugar. Take advantage of sports drinks at appropriate times for enhanced performance but choose water or other unsweetened beverages to quench daily thirst.

What Foods Should a Runner Eat?

Smart dietary choices through avoidance or limiting of foods appropriately help prevent unwanted symptoms from decreasing performance. Additionally, including more of certain types of foods can enhance athletic capabilities.

Nutrient Dense Carbohydrate Foods

Whole grains, fruit, starchy vegetables, legumes, yogurt and milk not only provide necessary energy to runners, but many other important nutrients. These additional nutrients support energy utilization, provide longer lasting energy, protect the immune system and support a healthy body.

Quality Protein

As the building block of the body, consuming adequate and frequent protein helps runners maintain, grow and repair muscle and other body tissue. Quality protein provides essential amino acids and other important nutrients necessary to optimal running performance. Look to include protein such as lean meat/poultry, legumes, nuts, seeds, eggs, seafood and dairy at most meals and snacks.

See More Protein Posts:

Healthy Fats

Unsaturated fats found in plant oils, nuts, seeds, seafood, avocados and olives help keep the skin, heart and brain healthy. Saturated fats in moderation may also play a role in keeping the body healthy. Runners will find that including an appropriate amount of fat in their diets lends to improved satisfaction at meals and helps them meet their increased energy needs.

Foods that Fight Inflammation

Runners are very familiar with inflammation as the body continually addresses the stresses associated with working out. Inflammation is the body’s way of healing and growing. However, chronic or excessive inflammation can negatively affect performance and increase risk of chronic disease.

Foods high in anti-inflammatory food components can decrease body inflammation. Plant derived foods such as whole grains, fruits, vegetables, legumes, nuts and seeds contain high amounts of antioxidants, polyphenols and phytochemicals to fight inflammation.

Fiber Rich Foods

Many Americans fail to meet fiber recommendations. Fiber offers a range of health benefits from supporting a healthy gut to helping prevent disease. A teenage runner’s fiber needs range from 26-38 grams of fiber daily. Eating plant-based foods throughout the day will help an athlete meet these recommendations.

Unsweetened Beverages

Runners cannot reach their peak performance when dehydrated. Drinking enough fluid throughout the day offers a competitive advantage and additional cognitive and health benefits. However, drinking sugar sweetened beverages can add excessive sugar and calories, which may decrease performance. Athletes should choose to drink mainly water and other unsweetened beverages such as milk, plant-based milk, herbal teas and a small amount of 100% fruit juice.

Katherine Harmer, RDN

I'm a Registered Dietitian Nutritionist with a love for coaching others to success in their health goals, especially teenage athletes. Tennis was my sport of choice in high school. Now I'm a little bit older, a little bit smarter, and a little bit worse at tennis.

Recent Posts