Resting metabolic rate (RMR) is the number of calories your body uses at complete rest to sustain basic functions such as breathing, circulation, and temperature regulation. It is measured through indirect calorimetry: while you rest quietly, you breathe through a mask or mouthpiece connected to a metabolic cart that analyzes the oxygen you consume and the carbon dioxide you produce. Because resting metabolism accounts for the majority of daily energy use in most people, a direct measurement is a more reliable starting point for nutrition planning than the generic equations that estimate it from height, weight, and age.
Resting metabolic rate testing is included in the Longevity program, where it forms part of the baseline metabolic and fitness assessment. The test is non-invasive, takes approximately 15 to 30 minutes, and is most accurate when performed in a fasted, rested state (specific preparation instructions are provided beforehand). Testing is run by the clinic Kinesiologist and read alongside your body composition (DEXA), extended metabolic blood work, and activity levels, so that caloric targets and nutrition recommendations are built around your measured metabolism rather than a population estimate. Where relevant, the measurement is repeated across the membership year to track how your metabolic rate changes with training, body-composition shifts, and dietary adjustments.