According to Dr. Berning, Associate Professor of Nutrition at the University of Colorado, to estimate how many calories you are burning the simple step-by-step formula below for women uses Basal Metabolic Rate (BMR) as a basis for the calculation.
What is metabolism?
Metabolism is the biochemical process of combining nutrients with oxygen to release the energy our bodies need to function. Metabolism is typically measured in kilocalories or, more commonly, calories. Total metabolic rate represents the calories needed for maintaining body functions, daily activity (occupational and lifestyle), and the energy cost of exercise or planned activity.
What is RMR or Resting Metabolic Rate?
Resting metabolic rate (RMR) represents the calories the body burns to maintain vital body functions (heart rate, brain function, breathing). In simple terms, it is the number of calories a person would burn if they were awake, but at rest all day. RMR can represent up to 75% of a person’s total metabolism if they are inactive or lead a sedentary lifestyle.
Why is it necessary to measure RMR?
Since RMR accounts for up to 75% of the total calories we need each day, it’s a critical piece of information to appropriately establish daily calorie needs, whether trying to lose or maintain weight.
How to calculate your calorie expenditure using resting basal metabolic rate
1. Calculate your weight in kilograms by dividing your weight in pounds by 2.2.
135lb women / 2.2 = 61.36 kilograms
2. Multiply 61.36kg by O.9. This is your average hourly calorie burn.
61.36 kilograms X .9 = 55.22 calories burned per hour
3. Multiply 55.22 by 24 and you get your approximate BMR (basal metabolic rate; RMR, or resting metabolic rate), the number of calories your body burns simply to stay alive – to keep your heart beating, your lungs expanding, your liver functioning and so on approximately 1,325 calories.
4. Now factor in your activity level:
a. lf you live a sedentary life, add in 10-20 percent of that number and you will have your daily calorie burn: 1,423 + 213 (15 percent of 1,325) = 1,523
b. lf you do light activity – you have, say, a desk job – but you walk 30 minutes a day – add 50 percent of your BMR; for you, this would be 1987 calories.
c. lf you have a moderately active job
for example, you’re a teacher and on
your feet much of the day and you do a
vigorous daily workout for at least 30
minutes, add 70 percent. This would
equal 2252 calories.
d. lf you have a very active job, such as a
mail carrier, and do daily vigorous workouts
for about an hour, add 80 percent
– which comes to 2,385 calories.
Therefore, based on your specific activity level, you are burning about 1987 calories per day. To measure your BMR, you will need to visit a gym or hospital equipped with machines that measure your caloric consumption through your respiration. The machine analyzes the composition of the gases in your breath to give an accurate BMR.