Simple fitness that works, from pregnancy to seasoned athlete.

Runners Diet: Nutrition Guidance for Runners

by Stephanie Margolis, R.D.

Running can be a convenient exercise, lace up the shoes and head out the door. You get a moment to move your body while also clearing your mind. You may have the right shoes, the ideal gear, but you also need to fuel your best to feel your best. A runner’s diet is extremely important whether you are running 3 or 13 miles.

Note: The information listed below is not specific to breastfeeding or pregnant moms. For more nutrition guidance visit our pregnancy and breastfeeding nutrition articles.

Distance Determines What to Eat and When

Good nutrition and hydration can make or break a run, no matter the distance. If you are dehydrated, you may experience cramping in your legs. Start your run with an empty stomach and you may find yourself completely gassed by the time you are just a mile in. If you eat the wrong thing before a run, you may experience some gastrointestinal distress. As with any workout, the right combination of nutrition and movement will help you reach your goals. 

The first thing many runners want to know is how much they should be eating to prepare for a run. If you are training for a 5k or 10k, you don’t necessarily need to “add” extra foods, or fuel during your run. However, the timing and content of your nutrients during the day can help make the most of your run.

>When you begin adding distance, as in training for a half or full marathon, that’s when you need to add in the gels/chews, sports drinks, and on-the-go nutrition. This typically starts when you are running for over an hour at a time. This is also when you need to increase your food intake to maintain your energy and prevent weight loss.

Looking for a running plan that includes toning, flexibility and 5k, 10k, and half marathon distances? Check out our Weekly Schedule for Athletes.



Before you start your run, you should feel neither starved or stuffed. Studies that have looked at pre-exercise meal timing have shown benefits from 2 hours before a run to as little as 30 minutes before hitting the road. This gives the body enough time to digest and use the food you just consumed. If you run after work but before dinner, you will want to have a small snack before a run. If you run first thing in the morning, a piece of toast or banana will usually suffice.

If you are looking for something more substantial, try:

  • Bagel + peanut butter
  • Banana + energy bar
  • 1 cup cereal + milk
  • Oatmeal + berries
  • Turkey + whole wheat bread

Things to avoid before a run include:

  • Sugary drinks and food
  • Spicy foods
  • Foods high in fiber
  • Lactose rich foods

What you drink before a run is equally as important. If you run later in the day, you want to start hydrating at least 4 hours before the run. If you run in the morning make sure you are hydrating before bed. The most accurate way to figure out your hydrate is to base it on your current body weight. The recommendation is 5–7mL per kilogram of body weight. But if you don’t want to mess with the math, if you run for 45 minutes you want to drink 17–20 ounces 2 hours before your run, and 10–12 ounces about 10 minutes before your run. 


Refueling your body after a run can help you recover faster and see the gains you are looking for. When you exercise, your muscles get tiny tears in them. When you refuel with protein, these tears are put back together with the amino acids leading to stronger, leaner muscles. Enjoying protein after your run can also ward off some of the hunger later in the day. When people begin a running routine or start to increase mileage, they often get hungrier throughout the day. Within 30–90 minutes after your run pick a snack or meal that is a ratio of 4:1, carbs:protein. For example, if you prefer a protein bar after a run, you will want it to have 40g of carbs and 10g protein. Other good recovery foods include: 

  • chocolate milk
  • bagel + peanut butter
  • hummus and carrots

Dive deeper into fueling before and after workouts.


Just as it is important to create a pre- and post-workout routine that works for you, it is vital to fuel your body well throughout the entire day. Food is our fuel. While it is hard to always remember this, especially when your favorite treats pass under your nose!

All the fuel our bodies need for life, as well as exercise, are found in the foods we eat and what we drink. There are several nutrients we need, but for starters we will break it down into three main groups: carbohydrates, protein, and fat.

Each group has a specific role in our bodies.


These are the fuel for your body. Runners burn a lot of carbs, especially if they are training for long distances. The exact number of carbohydrates you burn per mile depends on your fitness level, experience level, pace and running economy, but most marathon runners average around 110 calories per mile with about 75 percent of those calories coming from carbohydrates. A typical runner can store approximately 1800 calories worth of carbohydrate in their muscles, liver, and blood. That amount of carbohydrate will be depleted in about 22 to 23 miles which explains why most marathon runners “hit the wall” at that point in the race.

When in the midst of training, runners should be consuming a diet that is composed of between 65 and 70 percent carbohydrates. If you are a casual runner (averaging 3 miles per run), you can adjust that percentage to 50–60 percent carbohydrates. Remember, fruits and veggies have carbs, so filling half your plate with colorful produce is a great way to meet your carb needs.


Proteins are often called the building blocks of the body. Protein consists of combinations of structures called amino acids that combine in various ways to make muscles, bone, tendons, skin, hair, and other tissues. They serve other functions as well including nutrient transportation and enzyme production. Adequate regular protein intake is essential because it isn’t easily stored by the body. Various foods supply protein in varying amounts.  Complete proteins (those containing 8 essential amino acids) come mostly from animal products such as meat, fish, and eggs. Incomplete proteins (lacking one or more essential amino acid) come from sources like vegetables, fruit, and nuts. Vegetarian athletes may have trouble getting adequate protein if they aren’t aware of how to combine foods.

Athletes need protein primarily to repair and rebuild muscle that is broken down during exercise and to help optimize carbohydrate storage in the form of glycogen. Protein isn’t an ideal source of fuel for exercise, but can be used when the diet lacks adequate carbohydrate. This is detrimental, though, because if used for fuel, there isn’t enough available to repair and rebuild body tissues, including muscle.

  • The average adult needs .36 grams per pound of body weight per day.
  • Strength training athletes need about .64 to .82 grams per pound of body weight per day
  • Endurance athletes need about .54 to .64 grams  per pound of body of body weight per day
  • This typically turns out to be about 25 percent of an athlete’s total diet


Dietary fat is often blamed for many health problems; however, fat is an essential nutrient for optimal health. Adipose tissue (stored fat) provides cushion and insulation to internal organs, covers the nerves, moves vitamins (A, D, E, and K) throughout the body and is the largest reserve of stored energy available for activity. Fat is stored when we consume more calories than we use. There is an optimal level of body fat for health and for athletic activity. When that optimal level is exceeded, too much dietary fat can lead to problems with health as well as athletic performance

  • Saturated fats are found primarily in animal sources like meat, egg yolks, yogurt, cheese, butter, milk. This type of fat is often solid at room temperature. Healthy diet has less than 10 percent of daily calories from saturated fats.
  • Trans fats have undergone a process that increases its shelf life. This is called hydrogenation. These fats are known to raise your cholesterol and are found in processed foods, snack foods, cookies, some margarine, and salad dressings.
  • Unsaturated fats, including monounsaturated and polyunsaturated fat, are mostly sourced from plants. These fast are considered “good fats” because they are known to reduce cholesterol levels in the body. In this group are the omega-3 and omega-6 fatty acids.

Vitamins and Minerals

While vitamins and minerals are not used as fuel in the body, they play an important role in keeping us healthy. When you exercise, the body makes free radicals which damage the cells. Incorporating these nutrients can keep you pounding the pavement for longer:

  • Vitamin C & E: These are antioxidants that can help protect against free radicals and keep your immune system strong. 
  • Iron: Iron works to move oxygen to cells. If you aren’t getting the recommended 18mg per day, you run the risk of iron-deficiency anemia.
  • Calcium: We all know this plays a role in bone health, but did you know that getting the recommended 1000mg per day can help prevent stress fractures? 
  • Sodium: Sodium plays a big role in our body. It helps keep the water and electrolyte balance in our bodies. Anytime you sweat, you lose sodium and most of the time your body has no issue adjusting. However, if you run for more than 90 minutes, it is vital you are replacing the sodium via a sports drinks or coconut water.


Just as important as what you eat, is what you drink. Hydration is key when running especially if it is during the warmer months. Starting just 1 percent dehydrated can impact your performance. Also, if you start a run dehydrated, no amount of drinking fluids during your run will allow you to catch up with what your body needs. If you feel thirsty, have dark-colored urine, feel fatigued or dizzy, it is likely you are dehydrated. We talked about hydration earlier in this article, and I’m back again with the message of hydrate, hydrate, hydrate. If you get tired of plain water I’ve given several ideas to make your water more flavorful with a nutrition boost.


If you are pregnant or breastfeeding, you can still run as long as your doctor has not indicated otherwise. The most important thing is to listen to your body and pull back if you begin to feel too fatigued or uncomfortable. It is very important during this time to stay hydrated. If you are breastfeeding, a lack of hydration can lead to a lack of milk production. During pregnancy, even mild dehydration can leave you cramping and fatigued. Knowing this, add an additional 16 – 20 ounces of water to your day and be sure to drink regularly throughout the day. Carrying water with you while you run is one way to stay hydrated; however, if you begin your run dehydrated, no amount of water you drink during the run will adequately rehydrate your body.

If you are running just a few miles there is no need to adjust your caloric intake, unless you feel exceptionally hungry. If this is the case you may want to alter your meal timing, consuming a snack 30 – 60 minutes before a run and another snack 30–60 minutes after hitting the pavement. If you are training with higher mileage, you do want to add in about 300 calories. These would be additional calories beyond the extra calories your body needs in the second and third trimester. You may either do this by adding a snack or bulking up a meal. Keep these extra calories healthy by choosing produce, protein, whole grains, and good fats.

Are you a mom that wants to run again? Maybe you have never run before and a 10k is your goal. Check out our running workout programs and download our Complete Running Guide for Moms.