How Many Calories Do Runners Really Need?

Several factors go into being able to improve your performance as a runner. Consistent training with the right mix of speed work long runs, and easy runs are at the top of the list.

Rest and cross-training must also be incorporated to recover properly and be prepared for the hard sessions to come. Nutrition plays a large role in performance, as it is what gives us the energy we need to actually perform and to do it well.

Consuming the proper amount of carbohydrates and proteins is key to sustaining energy levels while making sure to include other key nutrients like iron and vitamins.

You may have been in the situation where you do well during training for a bit but frequently struggle to hit several workouts in a row. This is usually a sign that you are not eating enough. As volume and intensity increase during training cycles, the number of calories your body requires increases as well.

Even if you are on top of your nutrition game, it is easy to not meet your recommended calorie intake. Not eating enough calories can leave you fatigued on every run and increase your injury risk. But what is the right amount?

Calorie Intake

The right amount of calories a runner requires will depend on age, sex, weight, and activity level. This means it may be necessary to consume a fluctuating amount each day of the week since the intensity and length of runs and other workouts vary. The recommended daily calorie intake for a sedentary adult male ranges from 2200 to 2600 calories.

For females, the range is 1800 to 2000 calories. Therefore some distance runners may need close to 3000 or more calories most days of the week to maintain their weight and energy levels. This may seem like too much, especially to women, but it is what is necessary if you want to perform your best and not risk getting injured.

Weight Loss & Training

If you currently are overweight or obese, then a lower calorie intake is ideal until you reach your goal weight. This should be done carefully, as cutting calories too low can result in limited energy. This will only lead to having to skip workouts and not be able to run your hardest. Having too few calories risks losing muscle, which is what powers us through our workouts.

Therefore if weight loss is a goal when training for a race, then it should be done gradually. Unfortunately, it is safest to plan an extremely slow weight loss of about a half-pound per week.

Calorie Requirements Equation

Although calorie calculators you find online are used to get an estimate of the number of calories you need, it is usually in the ballpark of the right amount. The Harris-Benedict equation is a popular formula used to estimate your needs and takes into account your current activity level.

BMR for Men:    (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) + 5

BMR for Women: (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) – 161

BMR is your basal metabolic rate, which is the number of calories your body requires in order to function properly. Once you calculate your BMR with this formula, you can multiply by the different values according to daily activity level.

For men and women:

Sedentary/little to no extra activity: BMR x 1.2

Light exercise 1-3x/week: BMR x 1.375

Moderate activity 3-5 days/week: BMR x 1.55

Very active 6-7 days/week: BMR x 1.725

Hard exercise/physical job (2x/day training): BMR x 1.9

This method is a good way to determine how many calories you should have on each training day, since some runners train twice a day a few times per week, but also take a full rest day as well. Calorie requirements will be very different for each of these days.

Even with the above formula, the calorie requirement calculation can be wrong—either too high or too low. Everybody is different and some runners burn more calories per hour than others. Fitness levels, genetics, and present medical conditions can impact your calorie-burning rate.

A more accurate test is one where you sit for ten minutes with a mask over your face and your breathing is measured to determine how much oxygen you use at rest. Whether you use this method or the formula above, many times it is all about trial and error. It is best for runners to eat more than they think they need at first and see how their body responds rather than under eating to see if it is good enough.

You do not want to risk getting injured or wasting too many weeks not making progress due to not eating enough.

Types of Calories

Once you understand your individual daily calorie requirements, then it is important to fuel your body with the right types of calories. Limiting “empty calories” is key as these are considered calories with no nutritional value. Most packaged snacks, candy, soda, and chips are in this category.

Runners should focus on getting the majority of their calories, at least 60%, from high-quality carbohydrates in order to supply the muscles with enough glycogen. The other 40% can be divided evenly between lean proteins and healthy fats.

Proper fueling and hydration practices are necessary for performance improvement, injury prevention, and an overall healthy body.