Find out your biological age.
The PNOĒ Metabolic Breath Test is a clinical-grade diagnostic tool that analyzes the air you exhale to provide a precise roadmap of how your body processes oxygen and fuels, offering the unique benefit of eliminating guesswork from your health strategy by identifying exactly how to optimize your metabolism at rest and fuel your performance during activity. Now available at the Rhune Health office in Westlake Village, CA.
The Metabolic Guide
A plain-language guide to everything your Rhune metabolic assessment measures — what each metric captures, and why it matters for your health and performance.
Your assessment looks at how efficiently your body produces and uses energy — across your lungs, heart, nervous system, and cells. Use this guide to understand each measurement in your report.
Respiratory & Breathing
Ventilation efficiency
Ventilation efficiency reflects how well your lungs absorb oxygen and clear carbon dioxide — the ratio of total air moved (VE) to CO₂ exhaled (VCO₂).
It is a useful window on lung function, especially without a maximal exercise test. A high score suggests healthy gas exchange; a low score can flag inflammation, infection, or conditions such as COPD, asthma, or sleep apnea. Regular cardio and interval training, breathwork, and a healthy body weight support it; smoking, pulmonary or heart disease, and chemical exposure work against it.
Breathing coordination
Breathing coordination measures how regularly and efficiently you breathe at rest, and how well you coordinate the diaphragm and respiratory muscles.
How you breathe regulates nervous-system activation and whole-body oxygenation. Fast, shallow, erratic breathing activates the stress branch and lowers blood CO₂, which paradoxically reduces oxygen delivery to tissues; slow, steady breathing does the opposite. Regular exercise and breathwork improve it; poor ventilation, stress, and mood disorders degrade it.
Lung utilization
Lung utilization reflects how much of your lung capacity you use while resting, measured from your tidal volume — the air moved on each breath.
It is a contributor to oxygen absorption and to a high VO₂max. Lower utilization means less oxygen on board, which can be an early thread in respiratory, cardiovascular, and metabolic issues. Interval training, breathwork, and a healthy weight support it; respiratory disease, poor posture, and air pollution work against it. (Note: this metric saturates easily — most healthy people read at the ceiling.)
High Intensity Performance
High-Intensity Performance reflects how well your lungs and heart keep delivering oxygen across hard efforts, combining oxygen pulse and oxygen absorbed per breath.
Strong high-intensity delivery keeps you aerobic for longer at hard efforts — so you can train where VO₂max improves while limiting fatigue. Interval and heavy endurance work build it; it relies on healthy respiratory and cardiovascular systems.
Cardiovascular
Heart Rate Variability (HRV)
Heart Rate Variability is the beat-to-beat variation in your heart rhythm at rest — a sensitive readout of cardiovascular and autonomic resilience.
Higher HRV generally signals a more adaptable, well-recovered system and lower cardiovascular risk; lower HRV signals strain or reduced reserve. Exercise, sleep, omega-3s, breathwork, and a healthy weight raise it; alcohol, smoking, and unmanaged stress lower it. Single resting readings are noisy — trend it over time rather than over-reading one number.
Oxygen circulation
Oxygen circulation reflects how effectively your heart pumps oxygen-rich blood, derived from oxygen pulse (oxygen consumed per heartbeat).
A heart that delivers more oxygen per beat works efficiently; a plateau or decline as effort rises can signal cardiovascular deconditioning and warrants professional review. Cardio training, a healthy diet, and a healthy weight support it; cardiovascular or respiratory disease and smoking work against it.
Nervous System
Sympathetic / Parasympathetic activation
Sympathetic/Parasympathetic activation shows the balance between the two branches of your autonomic nervous system — the “stress” branch and the “recovery” branch — and which is currently dominant.
This balance reflects the psychosomatic stress your body is carrying. A recovery-dominant profile signals good rest and low stress load; a stress-dominant profile points to chronic stress, fatigue, and lower energy. Breathing is a direct lever: the upper lungs drive the stress branch, the lower lungs the recovery branch. Regular exercise, sleep, breathwork, and sunlight move it in the right direction; sleep loss and shallow breathing move it the wrong way.
Metabolism & Cellular Health
Metabolic rate
Metabolic rate shows how fast your metabolism runs — whether you burn more or fewer calories than predicted for your size, age, and sex.
A higher rate makes it easier to maintain a healthy weight, because you can cover normal intake without surplus. When it drops, weight gain becomes more likely on the same diet. Resistance exercise, adequate sleep, and sufficient protein support it; yo-yo dieting, extreme restriction, and excessive cardio suppress it.
Fat-burning Efficiency & Mitochondrial Function
Fat-burning efficiency reflects your cells’ ability to use fat as fuel — a hallmark of healthy mitochondria — measured from the oxygen and CO₂ balance in your breath.
It is one of the strongest indicators of cellular health and correlates with longevity and healthy weight. The more readily your cells burn fat, the better your metabolic resilience. Zone 2 training, adequate sleep, a clean diet, and sunlight support it; processed food, alcohol, and late heavy meals work against it.
Metabolic flexibility
Metabolic flexibility is your ability to switch efficiently between burning fat and carbohydrate as demand changes — across exercise intensities or between fasted and fed states.
It is a marker of mitochondrial health and a key protector against fat gain and metabolic syndrome. The more flexible you are, the better you convert food into energy rather than storing it. Aerobic fitness, intermittent fasting, resistance training, healthy weight, and sleep support it; processed carbohydrates, overeating, and poor aerobic fitness reduce it.
Movement Economy
Movement economy shows how many calories you burn while moving — the more economical, the fewer calories per unit of work.
It cuts both ways: high economy benefits endurance performance but can make weight loss harder; lower economy favors weight loss but, in athletes, can signal overtraining. Endurance training and clean movement patterns improve economy; read it against your goal.
Recovery Capacity
Recovery capacity reflects how quickly your heart rate and CO₂ return toward resting values in the first minutes after peak effort.
It predicts your resilience to training and your risk of chronic fatigue or overtraining. Better recovery means you can train more, more often, with less injury risk. Zone 2 training, sleep, and protein support it; chronic stress, under-recovery, and excessive training erode it.
Aerobic Capacity & Longevity
VO2peak
VO₂peak is the maximum amount of oxygen your body can absorb and use — the single best summary of cardiorespiratory fitness.
It is among the strongest predictors of longevity and all-cause health. The fitter your oxygen system, the lower your risk of chronic disease. Regular cardio and interval training, sleep, and the right nutrition raise it; inactivity, cardiovascular or respiratory disease, smoking, and stress lower it.
How Rhune reads your results
Every metric feeds the Quantum Advantage Method™ — our seven-pillar framework for whole-person performance and longevity.
Explore the Quantum Advantage Method →