Active calories vs. Resting calories: How to calculate your daily calories and meet your fitness goals

Most people interested in fitness have a general idea about how many daily calories they need, how many calories they should be consuming. It’s one of the first points of discussion even if you’ve only been on a diet (without the exercise component). Although people’s individual needs vary widely, the general averages are these—men burn between 2,000-2,500 calories a day, and women 1,600-2,000.

Now, these numbers will vary, based on metabolism, height, weight, and other factors, and the numbers do not include calories burnt during exercise. But they do include a little more activity than just the basic body movements.

If you want more granular numbers, then the resting calories—which the body needs to burn just to maintain basic functions like sleeping, breathing and blood circulation—make up for most of those calories needed in a day. Depending on the body’s Basal Metabolic Rate (BMR), this number could be between 1,300-2,000 calories a day. This is not to be confused by your Resting Metabolic Rate (RMR), which also includes calorie expenditure from small tasks like going to the door to collect a delivery.

“If it's being measured clinically in a lab, BMR is assessed first in the morning when a patient is at rest after an overnight fast and has had no exercise for the previous 24 hours. RMR is measured after at least 15 minutes of rest with few other restrictions and does not need to be measured before getting out of bed,” states a Verywellfit.com article titled RMR: What Is Resting Metabolic Rate?

If you read a history of the science of calories, then an important breakthrough in the understanding of our bodies’ energy needs was the ‘doubly labelled water method’ being adopted for human research. “The DLW method eventually was validated against the intake balance (I/B) method in humans (Schoeller and van Santen, 1982). The method has since been validated against indirect calorimetry and I/B in many different subject populations by several laboratories, with a demonstrated precision (coefficient of variation) of 2 to 8 percent (Schoeller, 1988),” states a study titled Doubly Labeled Water for Energy Expenditure.

With so many numbers being thrown around, you need to know just this: active calories is the number of calories burnt while performing an activity that isn’t more taxing than essential functions. But like any other metric, it’s important to know whether you really need to track this one or not.

Fitness trackers like Apple watches, Fitbits, and Garmins added this to their fitness tracking software, all of which ask you to put your weight, height, age, gender and other details into them for accurate stats. That is because the more muscle and size your body has, the more calories it will burn during physical activity. So people trying to lose weight can aim for a higher number of active calories to burn. Burning more active calories creates a caloric deficit through diet and exercise, leading to weight loss. The opposite is true for those looking to gain weight.

But like every other metric, one has to consider the downsides of excessively tracking it. “The earliest doubly labeled water studies among traditional farmers in Guatemala, the Gambia and Bolivia showed their energy expenditures were broadly similar to those of city dwellers. In a study published in 2008, Amy Luke, a researcher in public health at Loyola University Chicago, took this work a step further, comparing energy expenditure and physical activity in rural Nigerian women with those measures in African-American women in Chicago… hers found no differences in daily energy expenditure between populations, despite large differences in activity levels,” states a very interesting Scientific American article titled, The Exercise Paradox.

The article is written by Herman Pontzer, who is a professor of evolutionary anthropology at Duke University. One of the books he wrote is called Burn: New Research Blows the Lid Off How We Really Burn Calories. He provides some compelling evidence that metabolism does not really affect energy expenditure and that there is enough science to believe that the number of calories burnt, despite higher activity levels, seems to plateau at some point. It is a fascinating insight into how a higher activity level means one can train the body to burn the same amount of calories every day despite a fluctuating activity level.

The other (and possibly better) statistic to follow would be active minutes per day or per week. This is a more tangible number and you can calculate this even without a fitness tracker. 150-200 active minutes a week is a decent goal. These minutes are calculated by trackers using an elevated heart-rate compared to your average resting rate. But the clock and your body can also tell you that. Setting your own standard of what active minutes mean for you can be a progression here. For example, not counting your stretching routine as part of the active minutes quota after 2-3 weeks of consistent working out.

In case you’re looking for a ballpark though, then active calories spent per day should be in the region of 200-500 calories depending on your goals. My fitness watch tells me I burn around 250 calories on a moderately difficult gym day, and around 600 calories in an hour of 5-a-side football. Fitness numbers can be looked at from multiple angles, but the bottom line is that you need to move around enough to burn those extra 200 calories that your resting state does not need.

Pulasta Dhar is a football commentator and writer.