Basal Metabolic Rate Definition

Basal Metabolic Rate, or BMR, is your metabolic rate while at total rest, like sleeping. Measured in calorie expenditure, or calories burned, your BMR is responsible for approximately 60 to 70% of the total number of calories you burn in a day. That's a lot of calories burned without doing any exercises.

This calorie expenditure is used for digesting, breathing, pumping blood and maintaining body temperature. Basically, your Basal Metabolic Rate is the amount of calories used to sustain life.

Importance of Basal Metabolic Rate

Why is understanding your metabolic rate and understanding the definition important for weight loss?

In order to lose weight, you must create a calorie deficit. Meaning you must consume fewer calories than you burn.

Since BMR is responsible for approximately 60 - 70% of the calories you would burn in a day, in order to know your calorie intake for weight loss, you must start with BMR, or the calories you burn just to survive.

Creating a calorie deficit can be done one of several ways; 1. Consume fewer calories or, 2. Burn more calories – or do both, fewer calories consumed and more calories burned during exercise.

What Can Impact BMR?

In addition to age, gender, weight and height playing a role in your BMR, other things can impact this as well. For instance, if you are ill, your BMR can change during the illness.

Additionally, hormones can impact your basal metabolic rate. The thyroid gland produces Thyroxin, which is an important hormone to help your BMR.

If a person does not produce enough Thyroxin, their metabolic rate will slow down.

Certain medications may also impact your metabolism. Be sure to check with your doctor to see if any medicines you are taking impact your metabolism.

Genetics can play a role in your BMR. Some people will have a naturally higher metabolism while others will be slower. Although this may not seem fair it is what we are dealt and have to work with what was given to us.

Lastly, dieting can impact your basal metabolic rate. If done properly, you can actually increase your metabolism by eating healthy and adding exercise, both aerobic exercises and strength training.

But if you diet incorrectly, you will actually slow down your metabolism.

Don't Crash Diet

Many people make the mistake of going on a “crash” diet in hopes of a quick weight loss.

The problem is that if a person reduces their calorie intake by too much, the body reacts by going into survival mode, slowing down your metabolism and lowering your BMR.

What happens when you lose weight fast is that you are also likely losing muscle. This then lowers your lean body mass and in turn lowers your BMR.

A general rule is to never go below 1200 calories/day for women or 1800 calories/day for men, which are extremely low calorie levels.

What Can You Do To Raise BMR?

One thing you are in control of, and can have a positive effect on your metabolic rate, is your activity level. By adding exercise to your weekly routine, you are not only burning additional calories, which will help create that calorie deficit for weight loss, but you are increasing lean body mass. And since muscles burn more calories than fat, you are increasing your basal metabolic rate.

Be sure to read these other benefits to exercise.

Check out this free online Basal Metabolic Rate Calculator to see what calories you need to consume to lose weight.