What’s the Best Diet for Runners? Nutrition Tips and More

Before you grocery shop for optimal foods for running, it’s important to know the science behind them.

The three macronutrients important for your overall diet are:

• carbohydrates
• fat
• protein

Along with this, eating a diverse diet will ensure you’re also obtaining micronutrients and antioxidants, which play a key role in muscle function and recovery.

Carbohydrates

Carbohydrates are the body’s main energy source and are critical for long-distance running.

When you consume them, your body breaks down dietary carbohydrates into their simplest form, the sugar glucose.

Glucose is a vital energy source for humans. This is because your body needs it to produce the energy currency of your cells, called adenosine triphosphate (ATP) (1, 2).

During a run or exercise, your body may send glucose to muscle cells as an immediate source of energy. Any additional glucose in your bloodstream is sent to the liver and muscle cells to be stored as glycogen (1, 2).

During a run, your body initially pulls glucose from the blood to power working muscles. As levels of glucose begin to dip, the body begins to convert stored glycogen back into glucose through a process called glycogenolysis (1, 2).

Your VO2max is the maximum rate at which your body can use oxygen during exercise, and it increases with higher intensity exercise.

This limits oxygen available for energy production. As a result, your body turns to anaerobic (absence of oxygen) energy production, which mainly relies on carbohydrates (3, 4).

As your exercise intensity increases, such as in shorter distance runs and sprints, your body uses carbohydrates as a primary fuel source and fat as a secondary source (2, 3, 5).

Due to the shorter time duration of a sprint, most people will have adequate blood glucose and glycogen stores to support their run (2, 3, 5).

During lower intensity longer runs, your body increasingly relies on fat stores to produce energy. This might happen with runs greater than 6 miles (10 km), for example (3, 4, 5, 6).

Along with this, most long-distance runners will also need to refuel with simple sugars to sustain their run. That’s why many long-distance runners consume sports beverages or energy gel (5, 6).

Consuming about 45–65% of total daily calories from carbohydrates is a good goal for most runners (7, 8).

Fat

Stored body fat is another excellent fuel source, especially during long-distance running.

Generally, you should aim to get between 20–30% of your total daily calories from mostly unsaturated fats. Avoid eating less than 20% of your calorie intake from fat (8).

A low fat intake is linked with deficiencies in fat-soluble vitamins and essential fatty acids (8, 9, 10).

During long-lasting endurance exercise, your body turns to its fat stores as a primary source of energy.

This happens through a process called fat oxidation. It involves breaking down stored triglycerides into fatty acids, which your body then converts into glucose (1, 3, 5, 6).

While the process of fat oxidation is useful in long-distance running, it’s less efficient during high intensity exercise than using carbohydrates. That’s because fat takes extra time to be converted into energy, and this process also requires oxygen (8, 9, 10).

Furthermore, dietary fat is less efficient as a workout fuel than carbohydrates, which are used very quickly and are more readily available during exercise (8, 9, 10).

So, instead of consuming fat specifically to power your running, you may want to eat it as part of a balanced diet to support your body’s functions.

Dietary fat is crucial for:

• healthy joints
• hormone production
• nerve function
• general health

It also supports the absorption of fat-soluble vitamins (A, D, E, and K), making it a crucial component of your diet (8, 9, 10).

If you experience stomach upset, you may want to consume lower-fat meals in the few hours before a run. Instead, aim to consume higher fat meals during recovery hours (10).

Protein

Protein is not a primary fuel source during endurance exercise. Instead, your body uses it to support (11, 12):

• muscle growth and regrowth
• tissue repair
• injury prevention
• the production of oxygen-carrying red blood cells
• overall recovery

Your muscles break down as you run, which makes refueling with protein important for rebuilding that muscle. Without protein, the muscles are unable to rebuild efficiently, which can lead to muscle wasting, an increased risk of injury, and poorer performance (11, 12).

Though individual needs vary, most research suggests consuming around 0.6–0.9 grams of protein per pound (1.4–2.0 grams per kg) of your body weight per day.

This is sufficient for recovery and may help prevent muscle loss in extreme endurance athletes (8, 10, 11).

Micronutrients

Exercise stresses your body’s metabolic pathways, so you’ll need a diet rich in micronutrients to support their function.

While each athlete will have different needs, some micronutrients are especially important (8):

• Calcium. This is a main player in bone health and muscle contraction. Most people consume enough in their diet from calcium-rich foods, including dairy products and leafy greens.
• Vitamin D. Vitamin D is important for bone health because it supports calcium and phosphorus absorption. It may also contribute to muscle metabolism and function. You can get it from sun exposure, supplements, and vitamin-D-rich foods.
• Iron. This is crucial for the development of red blood cells, which deliver oxygen to working muscle cells. Distance runners, vegetarians, and vegans may need higher than the recommended dietary intake — greater than 18 mg per day for women and 8 mg per day for men.
• Antioxidants. Antioxidants help decrease cell damage caused by oxidation from intense exercise. Consuming antioxidant-rich foods — like vegetables, fruit, nuts, seeds — seems to be more effective than taking antioxidant supplements.
• Other nutrients and aids. Many athletes may use supplements or consume foods to enhance performance, such as beetroot, caffeine, beta-alanine, and carnosine. Some of these are backed by more research than others.

For most people, consuming a diet full of a variety of whole foods will ensure you’re getting enough micronutrients.

If you believe you may have a deficiency or want to try a new supplement, speak with a healthcare professional.

Summary

Carbohydrates are your body’s main source of energy during exercise. As you increase the distance and time of your runs, your body will also begin to use stored fat as fuel. Prioritizing your nutrition can help improve your performance.

Timing your eating well may make all the difference to your runs. Your timing will largely depend on:

• how long and far you run
• your personal goals
• your tolerance
• your experience

The best way to find what works for you is trial and error.

Pre-run nutrition

Most people who run for fewer than 60 minutes can safely exercise without eating beforehand. Still, you might want to have a small, carbohydrate-rich snack to provide a quick source of glucose. Examples include (13, 14):

• 2–3 Medjool dates
• applesauce
• a banana
• a glass of orange juice
• energy gel

If you plan on running for longer than 60–90 minutes, you’re going to want to have a small meal or snack that contains around 15–75 grams of carbohydrates at least 1–3 hours before your workout.

This will give your body enough time to digest your food (8, 13, 14, 15).

Examples of carbs to eat include:

• a fruit smoothie made with milk and a banana
• scrambled eggs and toast
• a bagel with peanut butter

You may want to avoid high fiber foods a few hours before a run because they take longer to digest and can lead to stomach upset during exercise. Examples include whole grains, beans, lentils, and some vegetables.

Finally, people who run longer than 90 minutes may wish to carb load a few days before an event.

This involves eating a large quantity of carbohydrates before a long-distance run to make sure your body is storing as much glycogen as possible to supply quick energy (8).

During carb loading, many people will aim to eat 3.2–4.5 grams of carbs per pound (7–10 grams per kilogram) of their body weight per day, 36–48 hours prior to their run. The best sources are complex carbohydrates, such as (8, 9, 10):

• potatoes
• yams
• whole wheat pasta
• brown rice
• multigrain bread
• low fiber cereals

During your run

The only macronutrient you need to focus on during a run is carbohydrates. What you consume should largely depend on the length and intensity of your run.

Here are general guidelines you can follow for different run lengths (8, 9, 10):

• Less than 45 minutes. No carbohydrate-rich food or beverage is required.
• 45–75 minutes. You might want a carbohydrate-rich mouth rinse or small sips of a sports beverage.
• 60–150 minutes. You may wish to top-off your blood sugar levels with 30–60 grams per hour of a sports beverage or energy gel.
• 150 minutes or longer. During long-distance endurance runs, you may need to replenish with upwards of 60–90 grams of carbs per hour. Most people prefer to replenish with carbohydrate-rich sports beverages, gels, chews, and bananas.

Post-run

Whether you eat right after a run will depend on the intensity of the exercise, how long you ran, and your personal preferences.

If you want to eat right away, try a small snack containing carbohydrates and protein, such as chocolate milk or an energy bar.

Within 2 hours after your run, try to have a meal that provides plenty of carbohydrates and protein.

Aim to get between 20–30 grams of protein. Research has shown this may promote increased muscle protein synthesis.

Some examples of protein-rich foods include (8, 9, 10, 16):

• beef
• chicken
• fish
• eggs
• tofu
• beans
• lentils
• tempeh
• protein powder (whey or plant based)

You’ll also want to replenish your glycogen stores by eating complex carbohydrates, such as whole wheat pasta, potatoes, brown rice, and whole-grain bread, which will provide a steady source of glucose for hours after your run (7, 8, 9, 15).

Summary

In most cases, the foods you eat before, during, and after your run will depend on many personal factors. Try a few of these pointers and tweak them as necessary to figure out what works best for you.

If you’re looking to improve your performance, here are some diet tips that might help (8, 17):

• Make sure you’re eating enough. If you’re constantly hungry or have low energy, this may be a sign you need to increase your calories.
• Hydrate. Staying hydrated is essential to optimal performance. Be sure to sip small amounts of water throughout your run to prevent dehydration. That said, avoid drinking too much at a time — this can lead to the dreaded “sloshing” sensation as you run.
• Replenish electrolytes. After 60 minutes of intense exercise, you may need to replenish your electrolytes (especially sodium and potassium) with food or a sports beverage, gel, or chew.
• Limit fiber and FODMAPs before your run. High-fiber and high-FODMAP foods may increase stomach distress during running. In some cases, working with a trained running professional might help you with gut training.
• Practice. In the weeks before a race or big run, try a few different foods and food timing to see what works best for you.
• Listen to your body. Sports nutrition guidelines aren’t set in stone. You may need to make adjustments based on how you feel and your personal goals. Consider working with a sports dietitian to create a personalized plan.

Summary

Eating enough, listening to your body, trial and error, staying hydrated, and several other tips may help improve your running.

The foods you eat play a major role in your running performance.

Depending on your personal and performance goals, the length of your run, and your level of experience, you’ll need to make sure you’re eating the right foods to help you run your best.

Since each runner is different, you may need to practice trial and error to see which foods and other diet factors work best for you.

Just taking a look at your nutrition habits may make all the difference.