Basal Metabolic Rate (BMR)

Comments Off on Basal Metabolic Rate (BMR) | Last Update: April 18, 2012

Human energy is spent in two major ways – on basil metabolic processes (energy to keep the heart beating, lungs inhaling and exhaling, the cells conducting their activities, and the nerves generating their continuous stream of electrical impulses), and on voluntary activities (walking, running, working, etc.).  The third way human energy is spent is called specific dynamic effect (SDE) and is the energy for metabolizing food; it is sometimes referred to as SDA (specific dynamic activity).

The basal metabolic rate (BMR) varies for each individual and with the individuals age and physical condition. It is lower when you sleep, higher when you are awake, even higher when you have a fever, and lower when you fast.  In general BMR is higher in people with greater lean body mass, with a large surface area,  with a fever or under stress.  It is lower when you loose lean tissue due to inactivity, fast, or are malnourished.

Four factors that affect your basil metabolism are:

1. Gender

Men have more muscle mass and lower percentage of body fat than women.  This means men, in general, men have a higher BMR.

2. Genes

Some people are born with a faster metabolism and some with a slower metabolism.  Your genetic metabolic rate cannot be changed.

3. Age

BMR declines with age.  People over 20 years old experience a drop in their metabolic rate of about 2 percent per decade.  That means people in there 60’s have a metabolic rate about 8 percent lower than when they were in their teens.

This is one reason why people gain weight as they age even though their diet and physical activity have not changed.

4. Exercise

The amount of exercise you get influences both your body weight and composition and  therefore your BMR.  Regular exercise maintains and builds lean tissue.  Lean tissue (muscle) burns more calories than fat tissue even when you are sleeping.

More lean tissue increases your BMR. If you have internet access, there are several websites that will let you estimate your BMR.  Type “basal metabolic rate” in your search engine.  You may be surprised by how many or how few calories your body needs for your BMR.

To estimate the total number of Calories you need or burn per day start with your BMR add 10 percent for specific dynamic affect and the number of calories for physical activity read the page about exercise.