BMR is taken first thing in the morning, after eight hours of sleep and a 12 hour fast while the subject is lying down.RMR does not require a sleepover, and is measured at any time of day following a three to four hour fast. BMR (basal metabolic rate) measures how many calories you burn at rest, or if you lied in bed all day.
How It's Measured. Measurement of BMR is more restrictive than RMR. Measuring BMR requires a clinical procedure that takes place in a hospital or laboratory and requires the subject to spend the night. BMR is taken first thing in the morning, after eight hours of sleep and a 12 hour fast while the subject is lying down. RMR does not require a sleepover, and is measured at any time of day following a three to four hour fast. Module C, Lesson 2  135 Basal or Resting Metabolic Rate Basal or resting metabolic rate (BMR or RMR) is the amount of energy per minute the body uses to maintain a quiet resting state. This is approximately 1 Cal per minute.  1 Because men, on average, have a greater muscle mass and a lower body-fat percentage than women, they generally have a higher basal metabolic rate. 2  Age. 3  BMR is greater in childhood than in adulthood. 4  After age 20, BMR is estimated to drop about 2 percent to 3 percent each decade. 1 After age 20, BMR is estimated to drop about 2 percent to 3 percent each decade. 2  Weight. 3  The more an individual weighs, the higher his or her BMR will be. 4  For example, the metabolic rate of very overweight individuals is generally higher than that of their normal-weight counterparts. What's Measured. Both BMR, and RMR, estimate the number of calories you burn at rest, but RMR takes additional factors into consideration when determining needs. BMR measures your basal energy expenditure, or BEE. BMR is taken first thing in the morning, after eight hours of sleep and a 12 hour fast while the subject is lying down. RMR does not require a sleepover, and is measured at any time of day following a three to four hour fast. The rate at which these processes occur is measured in calories per unit of time, and is most often given in calories per day. The term basal metabolic rate (BMR) is often confused and/or interchanged with RMR or resting energy expenditure (REE). 1 After age 20, BMR is estimated to drop about 2 percent to 3 percent each decade. 2  Weight. 3  The more an individual weighs, the higher his or her BMR will be. 4  For example, the metabolic rate of very overweight individuals is generally higher than that of their normal-weight counterparts. Or put another way, metabolic rate is an estimate of how many calories you would burn if you were to do nothing but rest for 24 hours. It represents the minimum amount of energy required to keep your body functioning. BMR is defined as Basal Metabolic Rate. BMR is synonymous with Basal Energy Expenditure or BEE. BMR measurements are typically taken in a darkened room upon waking after 8 hours of sleep, 12 hours of fasting to ensure that the digestive system is inactive, and with the subject resting in a reclined position. RMR can be defined as Resting Metabolic Rate. RMR is synonymous with Resting Energy Expenditure or REE. RMR measurements are typically taken under less restricted conditions than BMR and do not require that the subject spend the night sleeping in the test facility prior to testing. By Mark P. Kelly, Ph.D. Unless you have been living on an island or mountaintop somewhere (or simply don’t watch television), you’ve undoubtedly seen numerous infomercials talking about resting metabolic rate (RMR) and how one exercise or another will increase it, causing body fat to just melt away. 1 After age 20, BMR is estimated to drop about 2 percent to 3 percent each decade. 2  Weight. 3  The more an individual weighs, the higher his or her BMR will be. 4  For example, the metabolic rate of very overweight individuals is generally higher than that of their normal-weight counterparts. When comparing calorie estimations, RMR is slightly higher than BMR, but the difference is less than 10 percent, according to the National Research Council. While both RMR and BMR are considered estimations of your calorie needs, BMR is a more accurate measure because of the stricter procedures required to obtain it. BMR is taken first thing in the morning, after eight hours of sleep and a 12 hour fast while the subject is lying down. RMR does not require a sleepover, and is measured at any time of day following a three to four hour fast. The word metabolism refers to how much energy your body uses, or how many calories you burn in a day. A starting point to measure your metabolism is calculating BMR (basal metabolic rate), which measures how many calories you burn at rest, or if you lied in bed all day.  2. Before the Basal Metabolic Rate is taken, the person is required to stay at the testing facility, while in taking the Resting Metabolic Rate; the person can stay wherever he wants. 3. Basal Metabolic Rate requires the person to have at least 8 hours of sleep, while Resting Metabolic Rate does not. 4. Twelve hours of fasting is required before the Basal Metabolic Rate can be taken, while no fasting is required before taking the Resting Metabolic Rate. Also known as Resting Energy Expenditure (REE), Resting Metabolic Rate is measured under less restrictive conditions than Basal Metabolic Rate. A â it does not require the person to spend the night in the testing facility to ensure at least 8 hours of sleep and rest before. testing 
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resting metabolic rate is often measured instead of bmr because