Take the guess work out of nutrition! Discover how many calories your body requires at rest to guide fat loss, muscle gain, or weight maintenance with an RMR at the CHAMP Center!

RMR:

RMR: What It Is

Resting Metabolic Rate (RMR) is the number of calories your body uses at rest to maintain vital functions such as breathing, circulation, and cellular activity.

RMR is one component of Total Daily Energy Expenditure (TDEE), which consists of:

RMR: Calories burned at rest for basic bodily functions (~60–70% of TDEE)
Activity Energy Expenditure (AEE): Calories burned during movement and exercise (~20–30% of TDEE)
Thermic Effect of Food (TEF): Energy used to digest, absorb, and process food (~10% of TDEE)

Because RMR accounts for the majority of daily energy expenditure, it is a key metric for nutrition planning, weight management, and overall metabolic health.

An RMR test typically takes 45–60 minutes and uses indirect calorimetry. During the test, you rest quietly on a bed in a dimly lit room while a metabolic mask or hood captures oxygen consumption (VO₂) and carbon dioxide production (VCO₂). These measurements are then used to calculate your personal resting caloric expenditure. For the most accurate results, the test is performed in a fasted state, usually after at least 10–12 hours without food or caffeinated/sugary beverages.

At the CHAMP Center, we use the TrueOne® Parvo Medics metabolic cart, the same system trusted by NASA, US Olympic Training Centers, and leading research institutions worldwide. Our testing ensures professional-grade equipment, precise gas-exchange analytics, and industry-leading software for highly accurate RMR results.

RMR: Why It's Important

Moving Beyond Aimless Calorie Tracking

RMR is the largest contributor to the calories your body utilizes each day. Knowing your RMR takes the guesswork out of calorie counting by:

Guiding nutrition and energy needs. Your RMR provides a personalized baseline for the calories your body requires to maintain, lose, or gain weight, whether you’re an athlete or focused on overall health. It provides context for tracking calories in vs. calories out, so you can make informed decisions instead of guessing.

Supporting body composition goals. Accurate RMR data helps optimize macronutrient intake for fat loss, muscle gain, or performance, eliminating uncertainty.

Monitoring metabolic adaptations. RMR can change with age, training, hormonal shifts, or diet. Tracking it over time shows how your metabolism responds to lifestyle changes.

Pairing RMR results with activity tracking and body composition analysis (check out our packages) allows for precise energy balance, ensuring workouts are fueled appropriately and avoiding over- or under-eating.

RMR: Who Should Do It

An RMR test is ideal for anyone looking to better understand their metabolism and optimize caloric intake, including:

Individuals aiming for weight management: Those looking to lose fat or maintain a healthy weight can use RMR data to set realistic calorie targets.
Athletes and active individuals: Helps ensure sufficient fueling for training, recovery, and performance.
People with metabolic or hormonal concerns: Those with thyroid issues, perimenopause/postmenopause changes, or unexplained weight fluctuations can benefit from an accurate metabolic assessment.
Anyone curious about their metabolism: Even recreational exercisers can gain insight into how their body burns calories at rest.

Special Considerations for Women

Menstruation: RMR can fluctuate slightly across the menstrual cycle due to hormonal fluctuations. Testing during the same phase can help with precise longitudinal tracking, but it is not strictly necessary.

Pregnancy/Postpartum: For pregnant or postpartum individuals, RMR testing remains valuable; it provides insight into resting energy needs during periods of metabolic adaptation. Results should simply be interpreted in the context of pregnancy- or postpartum-related changes in metabolism.

RMR: Interpreting Results

Your Resting Metabolic Rate (RMR) represents the calories your body burns at rest to daily bodily functions and is the largest contributor to your Total Daily Energy Expenditure (TDEE). RMR breaks these calories down into fat and carbohydrate usage (protein is minimal at rest).

Why fat matters at rest:

Fat is the preferred fuel at rest, preserving carbohydrate stores for higher-intensity activity. Seeing more fat being used at rest shows your metabolism is functioning efficiently, while a shift toward carbohydrate reliance could indicate areas to optimize through nutrition, training, or lifestyle adjustments.

Key metrics on your report include:

RMR (total calories/day) → the number of calories your body requires at rest.
Respiratory Exchange Ratio (RER) at rest → shows the balance of fat vs. carbohydrate used for fuel at rest. It is calculated by dividing the VCO₂ (carbon dioxide produced) by the VO₂ (oxygen consumed).
- An RER ~0.7 indicates the body is primarily relying on fat for energy
- An RER ~1.0 indicates the body is primarily using carbohydrates.
- An RER ~0.85 indicates a mix of fat and carbohydrate utilization.

Since you are in a rested, fasted state, your body should be primarily utilizing fat for energy.

A lower RER at rest (~0.7–0.8) indicates healthy metabolic flexibility and efficient fat metabolism.
A higher RER at rest (closer to 1.0) suggests greater reliance on carbohydrates at rest, which can indicate metabolic stress, overfeeding, or impaired fat metabolism.

How to Use Your Results

Design personalized nutrition plans for weight loss, maintenance, or gain.
Adjust daily energy intake based on training load or lifestyle changes.
Track metabolic adaptations over time to evaluate how changes in diet, exercise, body composition, or hormonal status affect your metabolism.
Combine RMR with activity tracking, performance testing, and/or body composition to optimize overall energy balance and performance (see some of our packages here).