Running burns a lot of calories, and it takes a strategic nutrition plan to fuel your workouts and recover efficiently once you have finished your run.
But how many calories should a runner eat?
In this article, we will look at the caloric needs of runners so that we can answer the important question, “How many calories should a runner eat?”
We will cover:
- Do Calories Matter for Runners?
- How Many Calories Should a Runner Eat?
- Calculating Caloric Needs for Runners
Let’s jump in!
Do Calories Matter for Runners?
Calories can be a polarizing concept when it comes to weight loss.
When these two are equal, your weight will be stable.
When you’re eating a higher number of calories than you’re burning, you’ll gain weight, and when you’re burning more calories than you’re consuming, you’ll lose weight.Other people believe calories are only a small piece of the overall picture of weight loss, so worrying about “calorie math” is useless.
However, even if you set aside the potentially controversial relationship between calories and weight loss, it can still be quite valuable to know how many calories a runner should eat.
Calories are the energy the body needs when you run or do any form of physical activity.
If you’re not ingesting an adequate number of calories, your performance will suffer, and your recovery will be compromised.
If you’re eating too many calories, you will gain weight in the form of body fat, which can also hamper performance, depending on your current weight and body composition.
Therefore, knowing how many calories you need to support your running can absolutely be an important part of successful training.
How Many Calories Should a Runner Eat?
Let’s get down to the practical side of things: how many calories should a runner eat?
This is an impossible question to answer in a specific way for every runner because the number of calories you need depends on many factors.
The main factors to consider when determining how many calories a runner should eat include:
#1: Your BMR
Your basal metabolic rate, or BMR, refers to the number of calories your body burns every day just to sustain your life.
Processes like breathing and circulating blood to your tissues require a certain amount of energy.
Your BMR is mainly influenced by your body weight and composition, your age, and your sex.
The larger you are and the more muscle mass you have, the higher your BMR will be.
To make two simple comparisons, a runner who weighs 95 pounds will have a lower BMR than a runner who weighs 175 pounds, and a runner who weighs 180 pounds with 12% body fat will have a higher BMR than someone who also weighs 180 pounds but has 28% body fat.
In terms of sex, males typically have a higher BMR than females, primarily because of differences in lean body mass and the relative size of metabolically-active organs like the liver.
Finally, BMR usually decreases with age, largely due to sarcopenia (muscle loss).
The American Council on Exercise suggests that your BMR usually represents about 60-75% of the total number of calories you burn in a day. This percentage will vary based on how active you are, both in terms of your running training as well as general physical activity as you go about your day.
In terms of determining your BMR for the purposes of calculating the number of calories runners need to eat, you have to use a BMR or RMR (resting metabolic rate) formula to estimate this value unless you go to a physiology lab for metabolic testing.
Though the formula calculates RMR, this value is close enough to BMR to be used as a substitute.
The Mifflin-St Jeor formulas for each sex are as follows:
Men: (10 x weight (kg)) + (6.25 x height (cm)) – (5 x age (y)) + 5
Women: (10 x weight (kg)) + 6.25 x height (cm) – (5 x age (y)) – 161
You can also estimate your BMR or even your entire daily caloric expenditure with online calculators.
#2: Your Weight Goals
One of the most critical factors determining how many calories a runner should eat per day is the desired weight outcome.
Do you want to lose weight, maintain your weight, or gain weight?
Runners who have a goal of weight loss will need to generate a caloric deficit, meaning that they will be eating fewer calories per day than they are burning.
Runners who have the goal of weight maintenance will want to have a balance between the number of calories they are consuming and the number they are burning in a day.
Finally, runners who want to gain weight should eat a higher number of calories than they are burning every day in order to create a caloric surplus.
#3: The Amount of Training You Are Doing
Wearing a heart rate monitor while you run is one of the most accurate ways to estimate the number of calories you burn during your workouts.
You can also estimate the number of calories you burn running by using the METs values for different running speeds.
The Compendium of Physical Activities reports that running can be the equivalent of approximately 6-20 METS or so, depending on pace or effort level. For example, running 5 miles per hour, or 8 kilometers per hour, has a METs value of 8.3.
You can see the various METS for running at different paces in the table below:
|METS||Pace (mph)||Pace (kph)|
|6.0||4 mph (15 min/mile)||6.4 kph|
|8.3||5 mph (12 min/mile)||8 kph|
|9.0||5.2 mph (11.5 min/mile)||8.37 kph|
|9.8||6 mph (10 min/mile)||9.66 kph|
|10.5||6.7 mph (9 min/mile)||10.78 kph|
|11.0||7 mph (8.5 min/mile)||11.27 kph|
|11.5||7.5 mph (8 min/mile)||12.1 kph|
|11.8||8 mph (7.5 min/mile)||12.87 kph|
|12.3||8.6 mph (7 min/mile)||13.84 kph|
|12.8||9 mph (6.5 min/mile)||14.48 kph|
|14.5||10 mph (6 min/mile)||16.1 kph|
|16.0||11 mph (5.5 min/mile)||17.7 kph|
|19.0||12 mph (5 min/mile)||13.3 kph|
|19.8||13 mph (4.6 min/mile)||20.92 kph|
More information about this process and how to calculate the number of calories you burn running can be found here.
#4: Your Overall Activity Level
In addition to the number of calories you burn during your runs and other types of planned workouts, you also burn calories throughout the day as you perform your activities of daily living, job, etc.
Recall that BMR only constitutes the number of calories you burn per day, resting completely still in a bed for the entire day.
It takes additional energy, and thus burns calories, to get out of bed and do all of the various activities of daily living like going to work, preparing meals, basic hygiene, walking the dog, taking care of your children, etc.
The more movement you make throughout the day, including standing, walking, and carrying things, the higher your caloric needs will be.
To estimate the contribution of lifestyle physical activity to your overall caloric needs, most BMR or RMR equations have you apply an “activity multiplier.”
When you use the Mifflin-St Jeor equation to estimate your RMR, you multiply the value by the following scale factors for physical activity levels:
- Sedentary = RMR x 1.2
- Lightly active = RMR x 1.375
- Moderately active = RMR x 1.55
- Active = RMR x 1.725
- Very active = RMR x 1.9
For example, a runner who sits at a desk all day for work after running and does some light housework might multiply their BMR by 1.375 to account for their daily physical activity, but a runner who is a construction worker or who works on their feet all day after their run might multiply their BMR by 1.9.
Calculating Caloric Needs for Runners
Let’s walk through an example of calculating how many calories a runner should eat per day.
Our hypothetical runner, Joy, weighs 165 pounds (75 kg) and is 66 inches tall (167.6 cm) tall. She is 38 years old.
She runs about 5 miles (8km) per day at an average pace of 9 minutes per mile (10.78 kph).
Joy is a high school English teacher who is moderately active at her job and at home with her golden retriever, Dusky.
She wants to maintain her weight, but we will also look at the scenarios in which she wants to lose weight and gain weight.
First, we have to calculate her BMR (RMR) using the Mifflin-St Jeor formulas for women:
RMR= (10 x weight (kg)) + (6.25 x height (cm)) – (5 x age (y))– 161
RMR= (10 x 75 kg) + (6.25 x 167.6 cm) – (5 x 38 years) – 161
= 1,447 calories per day.
In terms of her running, we can use the METs value of running at a 9-minute per mile pace, which is 10.5 METs.
Using this METs values, we can calculate the number of calories Joy burns running based on her body weight and the duration of her workout using the equation to determine energy expenditure:
Calories Burned Per Minute = (METs x 3.5 x body weight in kilograms) / 200
= 10.5 METS x 3.5 x 75 / 200 = 13.8 calories per minute.
Then, because she runs 5 miles at a 9-minute-per-mile pace, we multiply the number of calories burned per minute by 45 minutes = 13.8 x 45 = 621 calories.
In terms of her physical activity level, we determined Joy is moderately active, which means we need to multiply her RMR by 1.55:
1,447 x 1.55 = 2242.8 calories
Adding the number of calories she burns running brings us to her total daily energy expenditure:
2242.8 + 621 = 2863.8 calories per day
The final step would be adjusting her calories based on her weight goals.
Since Joy is looking to maintain her weight, she should each about 2865 calories per day on her running days.
If she wanted to lose weight, we would reduce this number.
You lose one pound of fat for every 3,500-calorie deficit you create, so if you want to lose one pound per week, you need to eat 500 calories less than you burn per day.
For Joy, this would be 2865-500 = 2365 calories.
If she wanted to gain one pound per week, we would add 500 calories per day: 2865 + 500 = 3365 calories.
Are you ready to calculate your own daily calorie intake based on your personal goals? Give it a try!