What it is

Your resting metabolic rate (RMR) is the energy your body uses at rest to keep essential functions running, like breathing, circulation, and temperature control. PNOĒ measures it directly with breath analysis (indirect calorimetry), reading the oxygen you take in and the carbon dioxide you breathe out. It also shows whether your body is mainly burning fat or carbohydrate at rest.

 

Why it matters

Online calculators estimate RMR from age, height, weight, and sex, and their accuracy varies from person to person. A measured RMR gives you and your coach a more accurate starting point for your nutrition plan than a formula. It is a baseline, not a fixed calorie target: your total needs also depend on activity, training, and goals.

 

What to expect

You relax in a reclined position with your eyes closed, wearing a fitted mask connected to the PNOĒ analyzer and a heart-rate chest strap. Breathe normally and stay still; the measurement takes about 10 minutes. For accurate results, have nothing but water for at least 5 hours beforehand, skip caffeine, nicotine, and energy drinks for 5 hours, and avoid intense exercise or any workout over an hour in the 24 hours before.

 

Before you book

RMR can be tested at any time of day, but retests should be done at the same time as your first test so results compare cleanly. Keep taking your medications as usual and tell us what you take; never stop a prescription unless your clinician tells you to. If you are sick or have new symptoms, let us know and we will reschedule.