Basal Metabolic Rate (BMR) Explained
Let’s take a minute to describe basic metabolic rate. This is a term used to describe the amount of energy (calories) your body is burning at rest, without any physical activity or energy of digestion. It makes up about 70% of your bodies energy expenditure per day, so that should help explain the importance of this process.
The purpose of BMR is to maintain the vital organs of the body. These organs include the heart, lungs, liver, kidneys and brain; among others. It also helps maintain your skeletal muscle, sex organs and skin. Your thyroid hormone is a major modulator of your basal metabolic rate, as are other hormones including cortisol, adrenaline and growth hormones.
BMR varies wildly from person to person. Things that are associated with a higher BMR: increasing muscle mass, height and weight. Increasing age is associated with a lower BMR. It is is generally higher in men than women. Other factors such as illness, environment and stress can influence your bodies BMR. Genetics also plays a role in BMR, as people with similar physical builds can have significantly different BMRs.
BMR can be estimated using BMR or total daily energy expenditure calculators. If you google it, there are many available. One example of a mathematical model used to estimate it is the harris benedict equation. Another example is the respiratory quotient.
In summary, BMR is essentially everything your body has to do except digest food and physical activity. It makes up 70% of your daily energy expenditure. Knowing your BMR can help you estimate how many calories your body uses in a day.