What is resting metabolic rate and how to increase it?

In this article you’ll find the answers to the following questions:

• What exactly is resting metabolic rate (RMR)?
• What is the main difference between resting metabolic rate and basal metabolic rate (BMR)?
• What are the factors that affect your RMR?
• How strength training increases the resting metabolic rate?
• How to calculate your RMR?
• How can you increase your metabolic rate?
• How to use your RMR to lose fat or gain muscle (importance of knowing this number)?

What is resting metabolic rate (RMR)?

Your resting metabolic rate (RMB) is the rate at which you burn calories on essential body functions, such as breathing, organ function, and blood circulation while you are awake and in a nonfasting state. In other words, your resting metabolic rate is the number of calories your burn over 24 hours while lying down but not sleeping. It accounts for 60–75% of the calories you burn daily.

There is another term – basal metabolic rate – which is something slightly different. Your basal metabolic rate (BMR) is the rate at which you burn calories on essential body functions during sleep. However, most methods measure the resting metabolic rate (RMR). RMR is typically only slightly higher than BMR and is determined under less rigorous conditions.

What determines resting metabolic rate?

A wide variety of factors affect your RMB. Age, sex, genetics, hormonal changes, body size, body composition, temperature, altitude, illness, medication, food and caffeine intake, and cigarette smoking are among most important factors that dictate the rate at which you burn calories on essential body functions. Certain factors you can’t alter — such as age, sex, and genetic — but the rest you can.

However, the most important factor that determines your RMR is the amount of fat-free mass (lean body mass) you have (muscle, bone and vital organs). This is calorie burning tissue so the more fat-free mass you have the higher your RMR will be. Therefore, your RMR will decrease as you lose muscle.

Effect of strength training on resting metabolic rate

Strength training increases the resting metabolic rate (RMR) by increasing muscle mass. Muscle has a higher energy requirement than fat tissue, so the more muscle you have, the higher your metabolic rate. In other words, since the normal resting energy requirements of muscle are high, people with more muscle mass should definitely burn much more more calories at rest and throughout the day.

Research has shown that adding 1.4 kg of muscle increases RMR by 7 per cent and daily calorie requirement by 15 per cent. At rest, 0.45 kg of muscle tissue requires 35 kcal/day. During exercise, energy expenditure rises dramatically – five to 10 times above the resting level. Thus, the more muscle tissue you have, the greater the number of calories expended during exercise and at rest.

How to calculate resting metabolic rate?

If you don’t like math equations, the easiest way to find your RMR is to use a quick and easy resting metabolic rate calculator. In order to use RMB calculator, you simply need to know your height, your current weight, your age, and your gender. However, be aware that even the best RMR calculators provide only a best guess. Therefore, you should use this calculators as a guide only.

If you love math, you can also calculate resting metabolic rate on your own. Although you can get a very good estimation of your basal metabolic rate simply by multiplying your body weight in pounds by 10, the Harris-Benedict equation provides a more precise, although still imperfect, approximation.

• Men: RMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)
• Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)

In these equations weight is measured in kilograms, height in cen­timeters, and age in years. The result is in kcal/day.

How can I increase my metabolic rate?

Making small lifestyle changes and incorporating these tips into your routine can increase your metabolism. Having a higher metabolism can help you lose weight and keep it off, while also giving you more energy.

How to use your RMR to lose fat or gain muscle?

Once you use your RMR to determine your total daily energy expenditure (TDEE), you can make sure that the nutrition plan you follow is appropriate for your level of energy expenditure and that it isn’t giving you too many or too few calories (depending on your fitness goals). Being armed with this knowledge, rather than guesstimating or blindly following a plan without scaling it to your individual needs, can make or break your muscle gains or fat loss.

Summing up

Resting metabolic rate represents the minimal amount of energy required to sustain vital bodily functions such as blood circulation, respiration, and temperature regulation while you are awake and in a nonfasting state. RMR is closely related to one’s muscle mass, so we actually have a bit of control over our resting metabolism in that we can increase our own muscle mass. RMR is also the starting point when trying to calculate your daily calorie needs.