Metabolism test

Resting metabolic rate (RMR) test

Measures how many calories your body burns at rest, from your breath. You just recline and breathe for about 20 minutes.

Book an RMR test See pricing

TimeAbout 30 minutes at the studio

AccuracyWithin about 5%

ResultsSame day, in your dashboard

Client resting in a recliner with a VO2 Master mask during a BodyStats RMR test

Why it matters

Your resting burn is 60 to 75% of the calories you use each day. Get it wrong and every diet built on it is off too.

The test measures the oxygen you use and the carbon dioxide you breathe out, which converts directly into calories. So you can set a deficit, maintenance or surplus that fits your body, not an average.

Where your calories go each day

60 to 75%At restMoving

Resting burn: what this test measures
Moving: exercise, walking, everyday activity
Digesting food: about 10%

Online calculatorCan be off by 200 to 500 calories a day

BodyStats RMR testMeasured from your breath, within about 5%

How the test works

Nothing to do but lie back and breathe. Most people close their eyes.

Quiet private testing room with a cream recliner and a small lamp

Settle in

You recline in a quiet, private room. The first few minutes let your body calm down, and they aren’t counted.

BodyStats technician fitting a VO2 Master mask on a client

Breathe normally

We fit a soft VO2 Master mask. It measures the oxygen you use with every breath, and a heart rate strap tracks your heart.

Client giving a thumbs up from a leather lounge chair during an RMR test

Get your real number

We use your steadiest 5 minutes of breathing, so a cough or a fidget doesn’t count against you.

Watch your metabolism live

We built our own testing app, BodyStats Lab. You see your number as you breathe and watch it settle as your body relaxes.

Calories a day, updated with every breath
How you compare with what’s expected for your size and age
Heart rate and heart rate variability (HRV)
Oxygen and breathing, minute by minute

BodyStats Lab app during an RMR test: 1,868 calories a day, 9% above expected, with a chart of calories through the test — Your calories a day, as you breathe

BodyStats Lab app heart rate tab: 59 bpm now, 58 lowest, 42 ms HRV — Heart rate and HRV as you relax

BodyStats Lab result: resting metabolic rate 1,869 kcal a day from the steadiest 5 minutes, variation 3%, steady

Your steadiest 5 minutes

Breathing is never perfectly even, so we don’t average the whole test. After the settle-in, the app finds the 5 minutes where your breathing was steadiest and uses those for your result.

Not countedYour result comes from here

Your report

Three pages, in your BodyStats dashboard the same day. Save it as a PDF and share it with your coach or dietitian.

Sample RMR report page 1: calories at rest, metabolism speed, measured against predicted, and daily calories by activity level — **Your results**Calories at rest, how fast your metabolism is for your size, and daily calories for your activity level.

Sample RMR report page 2: calories and heart rate through the test, how it works and what the numbers mean — **Your test**Calories and heart rate through the whole test, with the 5 minutes we used.

Sample RMR report page 3: breathing and heart, including oxygen per breath, heart rate variability and fun facts — **Breathing and heart**Oxygen in every breath, resting heart rate, HRV and a few fun facts.

Headline

Calories at rest

Your resting burn in calories per day, and how it compares for your age and sex.

Targets

Daily calorie targets

Pick your activity level and goal to get targets to cut, maintain or gain.

Detail

Full test graphs

Breathing and gas-exchange graphs you can share with your coach or dietitian.

Sample report from a practice test.

At our studios

Real RMR tests at BodyStats.

Client in a recliner by the studio window wearing a VO2 Master mask

Close-up of a client wearing the VO2 Master mask during an RMR test

Client lying back in a reclining chair during an RMR test

Testing room with a leather lounge chair and ottoman

Before you come

Your number is only as good as your rest. These keep it accurate.

6 to 8 hNo exercise before your test

2 to 3 hNo food before your test

No caffeineAnd no pre-workout

WaterIs fine, drink as usual

Full instructions: test preparation guide.

Questions

How accurate is it?

Within about 5%. Online calculators estimate from averages and can be off by 200 to 500 calories a day, especially if you carry more or less muscle than average.

Do I need to fast?

Yes, for 2 to 3 hours. Food raises your metabolic rate for a while and would skew the number. Water is fine.

How long does it take?

About 20 minutes of measuring, and about 30 minutes at the studio in total.

What’s the difference between RMR and TDEE?

RMR is what you burn at rest. TDEE adds everything you do on top of that. Read RMR vs. TDEE.

Know your real number

Book an RMR test in Vancouver or Toronto.