Resting Metabolic Rate Tests
The Resting Metabolic Rate (sometimes called Basal Metabolic Rate (BMR)) test is designed to measure how many calories you are actually burning at rest. With this information we can look at how much activity you are engaged with daily, and calculate how much you need to eat for your health and fitness goals.
Resting Metabolic Rate Tests
The Resting Metabolic Rate test is designed to measure how many calories you are actually burning at rest. With this information we can look at how much activity you are engaged with daily, and calculate how much you need to eat for your health and fitness goals.
What is RMR Testing?
The Resting Metabolic Rate test uses a method called Indirect Calorimetry. This means that it is collecting and measuring your breath in order to measure how much oxygen is in it after you breathe out. The machine has sampled the air, so it knows how oxygen rich the air you are breathing in is, and by looking at the difference between oxygen in the air breathed in, and oxygen in the air breathed out, it can measure how much oxygen your body has absorbed from that breath. By adding these all up, it is able to see what your body is taking on at rest over time, and it converts this to a calorie figure.
How Does RMR Testing Work?
Our bodies require 208ml of Oxygen in order to expend 1calorie. This is a tried and tested constant. Because we know this we can conclusively say that if we have taken in 2080ml of Oxygen, and then breathe out 2080ml of a mix of Oxygen and Carbon Dioxide which contains 1040ml of Oxygen, we know in that time, we have consumed 5 calories.
Why would I get a RMR test?
As you’ve probably seen, you can on some websites plug in your age, height, weight, and sex, and it’ll spit out a Resting Metabolic Rate figure. The problem with this is that it is based on averages for the population. There are many things which affect our resting metabolic rate: genetics; hormone function; past history of eating. All these will change your metabolic rate, and so the averages don’t always work for people. You would get your resting metabolic rate measured if you feel like your metabolism is faster or slower than the average, and you’d like to find out just how fast/slow it is.
Examples of when a Resting Metabolic Rate test would be useful
- Katy is a 28 year old woman. She has in the past used crash diets, and very low calories to lose weight. This time this approach doesn’t seem to be working, and even with quite low calories, Katy is not losing weight. She suspects she’s got a slow metabolism and would like to be scientific in her approach to weight loss this time.
- Max is a 24 year old man. He is trying to put on some muscle and has used online calculators to work out a moderate surplus of calories based on the expected metabolic rate. However he has been unable to add any weight despite high protein and intensive weight training. He suspects he’s got a fast metabolic rate, but wants to test it to see.
- Susan is a 45 year old woman. She has known hypothyroidism, and is working with a doctor to get treatment for this. However she has been putting on weight, and isn’t sure why. She wonders if her thyroid issue is affecting her metabolic rate and would like to get it tested to be sure.
- Graham is a 65 year old man. He is active, but has been losing some strength and mobility a bit recently. He has been eating the same, but is now putting on fat, and wants to know why. He worries that his metabolism is slowing down with age, and wants to get it checked.
What is the Metabolic Testing procedure?
When you come in, we’ll sit you down for a few minutes before starting the test to let you relax. You’ll then be given a nose clip to ensure that all your breathing is through your mouth, and a breathing tube which you’ll have to breathe into normally for about 10 minutes.
While taking the test we’ll encourage you to relax, recline, and rest as much as possible.
It is helpful to not have caffeine or other stimulants in the system when taking the test as this will affect the readings. Ideally you should not have exercised that day either, as this will also increase your metabolism for several hours post-workout.
What is RMR Testing?
The Resting Metabolic Rate test uses a method called Indirect Calorimetry. This means that it is collecting and measuring your breath in order to measure how much oxygen is in it after you breathe out. The machine has sampled the air, so it knows how oxygen rich the air you are breathing in is, and by looking at the difference between oxygen in the air breathed in, and oxygen in the air breathed out, it can measure how much oxygen your body has absorbed from that breath. By adding these all up, it is able to see what your body is taking on at rest over time, and it converts this to a calorie figure.
Why would I get a RMR test?
As you’ve probably seen, you can on some websites plug in your age, height, weight, and sex, and it’ll spit out a Resting Metabolic Rate figure. The problem with this is that it is based on averages for the population. There are many things which affect our resting metabolic rate: genetics; hormone function; past history of eating. All these will change your metabolic rate, and so the averages don’t always work for people. You would get your resting metabolic rate measured if you feel like your metabolism is faster or slower than the average, and you’d like to find out just how fast/slow it is.
Examples of when a Resting Metabolic Rate test would be useful:
- Katy is a 28 year old woman. She has in the past used crash diets, and very low calories to lose weight. This time this approach doesn’t seem to be working, and even with quite low calories, Katy is not losing weight. She suspects she’s got a slow metabolism and would like to be scientific in her approach to weight loss this time.
- Max is a 24 year old man. He is trying to put on some muscle and has used online calculators to work out a moderate surplus of calories based on the expected metabolic rate. However he has been unable to add any weight despite high protein and intensive weight training. He suspects he’s got a fast metabolic rate, but wants to test it to see.
- Susan is a 45 year old woman. She has known hypothyroidism, and is working with a doctor to get treatment for this. However she has been putting on weight, and isn’t sure why. She wonders if her thyroid issue is affecting her metabolic rate and would like to get it tested to be sure.
- Graham is a 65 year old man. He is active, but has been losing some strength and mobility a bit recently. He has been eating the same, but is now putting on fat, and wants to know why. He worries that his metabolism is slowing down with age, and wants to get it checked.
How does it work?
What is the procedure?
While taking the test we’ll encourage you to relax, recline, and rest as much as possible.
It is helpful to not have caffeine or other stimulants in the system when taking the test as this will affect the readings. Ideally you should not have exercised that day either, as this will also increase your metabolism for several hours post-workout.
How Accurate is Metabolic testing?
Indirect Calorimetry (IC: what we are doing with the RMR test) is considered the gold standard of measuring your Resting Metabolic Rate. This study in the Iranian Journal of Public Health compared the standard equations to indirect calorimetry and found that in certain populations the standard equations were wildly inaccurate.
Further, there are countless studies which show that IC is understood in the scientific community as the gold standard for measuring a person’s RMR and getting to a detailed total Energy Expenditure.
How much does RMR testing cost?
We have tried to keep our pricing as easy to understand as possible. For a full schedule of prices for all tests/scans please click here, but the basic pricing is below:
| Number of tests | Cost | Validity Period |
|---|---|---|
| 1 Scan/Test | £149 | 12 months |
| 2 Scans/Tests | £269 | 12 months |
| 3 Scans/Tests | £359 | 12 months |
| 4 Scans/Tests | £449 | 12 months |
How else can I find this information?
The question we are seeking the answer to with the RMR test is ultimately ‘How much should I be eating?’
The only other way to do this is based on estimates which are based on population samples. Ever had a doctor or someone else tell you that because you are a man, you should be consuming 2500 calories, or 2000 for a woman?
But there are so many factors which could make this ‘average’ very wrong. Levels of thyroid hormone, insulin, cortisol, and many others will affect your metabolism. The amount of muscle mass, you have and a host of other factors can have a dramatic effect on this.
What do you get at the end?
At the end of your RMR test you’ll get a report showing you exactly how many calories you are burning at rest. This will give you accurate guidance on how many calories you should be eating in order to maintain weight or lose.
As you can see from the example below – this client had a much faster than average metabolism owing to a very significant amount of muscle mass.
Check out out Blog on how you might create an action plan from your RMR test results
What’s the difference between a Resting Metabolic Rate test (RMR) and Basal Metabolic Rate test (BMR) ?
Sometimes you will hear the term ‘Basal Metabolic Rate’ or BMR test. These both refer to the same value – the number of calories you burn when you are fully at rest. The only difference between these is the manner in which they are collected. A Basal Metabolic Rate test is what would be used in scientific papers. It would require you to attend a sleep lab, and the reading would be taken immediately upon waking. The Resting Metabolic Rate test is the “field-test” version of the same thing. We would usually try to get you a morning appointment, and we ask that you do not have any caffeine or food beforehand. Nevertheless, we will apply a factor for the activity you are doing when we take the test (sitting quietly).
What do you get at the end?
As you can see from the example below – this client had a much faster than average metabolism owing to a very significant amount of muscle mass.
What’s the difference between Resting Metabolic Rate (RMR) and Basal Metabolic Rate (BMR) ?
Sometimes you will hear the term ‘Basal Metabolic Rate’. These both refer to the same value – the number of calories you burn when you are fully at rest. The only difference between these is the manner in which they are collected. A Basal Metabolic Rate measurement is what would be used in scientific papers. It would require you to attend a sleep lab, and the reading would be taken immediately upon waking. The Resting Metabolic Rate test is the “field-test” version of the same thing. We would usually try to get you a morning appointment, and ask that you not have any caffeine or food beforehand. Nevertheless, we will apply a factor for the activity you are doing when we take the test (sitting quietly).
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