This is part 2 of Resting Metabolic Rate (RMR), Body Mass Index (BMI) and Total Daily Energy Use

Even sitting uses energy

Your Resting Metabolic Rate is the amount of energy you consume just quietly sitting still. It is calculated here using a formula developed by Mifflin and uses your weight, height, age and gender. Results show the energy you consume per hour and per day just sitting doing nothing.

Development of other versions of this calculator that are more specific for individuals who are overweight and obese or have certain medical conditions like Rheumatoid Arthritis or who body build or are athletes would be very useful.

Please note that – RMR calculated here for athletes and body builders can be a little LOW while on the other hand, if your BMI is over 30 with extra fat weight, then your RMR shown here will be a little HIGH. This is because extra lean muscle mass burns more calories while extra fat weight uses very few extra calories.

MET values make it all so simple

The MET values are grouped into common daily activities. They are sorted from lowest to highest within each category and are shown in green. MET values are simply a multiple of your RMR. For instance, if you perform an activity that has a MET value of 2, you will use twice as much energy than you would if you were just sitting still.

The energy you use sitting still is equivalent to your RMR. The activity descriptions use either metric values like metres and kilograms or imperial values like pounds and mph.

What are “Calories burned” and METs

In the previous article “What are Calories” we explored kilojoules versus calories. Calories burned indicates the amount of energy used during a specified activity in an individual. This energy expenditure during physical activity is approximately equal to your Resting Metabolic Rate (RMR) multiplied by the intensity of an activity (expressed as a MET value) for a given amount of time.

METs represent how hard your body is working. The larger the MET value, the more kilojoules you consume in a given time.

How it works

Metabolic Equivalent of Tasks or MET values is based on scientific research that has focused on quantifying the intensity of many common days to day physical activities. They are designed to show calories burned during an activity as multiples of our custom RMR. It’s fascinating to see which activities consume the most energy.

The energy cost of physical activity for a “statistically average human” is estimated in many online “calorie burned calculators” as the MET value of the activity multiplied by your weight (in Kg) multiplied by the time of activity (Hrs).

We, however, have taken a different approach. “Unique Individual” are the keywords here. Each human being has a specific resting energy signature. In other words, some calories we burn while we are at rest is unique to us, and this is called our Resting Metabolic Rate (RMR).

RMR versus BMR

Another term that is often used interchangeably with RMR is your Basal Metabolic Rate (BMR). For an individual, BMR is the rate at which the body expends energy to sustain basic life processes such as breathing, heartbeat, kidney function, blood circulation and staying awake.

BMR values do not take into account the energy costs of digesting food or thermoregulation (keeping you at a stable temperature) or any physical activity (even sitting still).

In contrast to the BMR, the requirements for defining an RMR in a person are not as stringent. The person may be sitting and have eaten in the last 2-4 hours. They just need to be comfortable and relaxed. It is estimated that a RMR for a person is about 10% greater than their BMR.

Where BMR accounts for approximately 50% – 70% of total daily total energy expenditure (TDEE), the RMR is thought to account for between 65% – 80% of TDEE.

METs come to the rescue

Now MET values can range between 1 to 20. Sitting studying uses 1.8 METs while sleeping is rated at only 0.9 METs. Running a 10-minute mile (9.66 km/h) uses nearly 10 METs. Cooking or food preparation with moderate effort uses 3.5 METs as does vacuuming, washing a car, washing windows and cleaning the garage with moderate effort.

Seeing a value of 4 METs displayed on a treadmill means you’re working four times as hard than if you were at rest, AND you’re consuming four times as much oxygen and burning four times as many calories as you would be at rest.

To estimate the calories burned in an individual during a specific activity for a specified amount of time with as much precision as possible, we need to accurately as possible determine individual BMR or RMR while taking into account other individual factors.

Like – chronic illness, burns and injuries, infection or inflammation, body composition and lean muscle mass, whether the person is dieting, thyroid hormone levels, efficiency of movement and geographic or environmental conditions in which the activities are performed.

RMR and TDEE calculators

We can then multiply RMR by the duration and by the intensity of physical activity(MET value). This will give us a fairly good estimation of the “calories (or kilojoules) burned” during this activity expressed as a multiple of our unique RMR. Estimating calories consumed over a 24hr period during various categories of activities (like sleeping, walking, etc.), then allows us with a fair degree of precision to predict the TDEE for an individual.

Special thanks to Stephen Herrmann, Ph.D. at the Dept. of Internal Medicine, Cardiovascular Research Institute, Center for Physical Activity and Weight Management, University of Kansas Medical Center. For the latest evidenced based information and research on MET values see The Compendium of Physical Activities

REF: Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett Jr DR, Tudor-Locke C, Greer JL, Vezina J, Whitt-Glover MC, Leon AS. The Compendium of Physical Activities Tracking Guide. Healthy Lifestyles Research Center, College of Nursing & Health Innovation, Arizona State University. Retrieved