Metabolic & Fitness Testing
Stop estimating. Measure how your body actually uses energy and oxygen.
Metabolism + VO₂ testing uses portable breath analysis to measure how your body uses energy at rest and how efficiently your heart, lungs, and muscles use oxygen during exercise.
Instead of relying on generic formulas, wearable estimates, or “calories burned” guesses, you get objective information about your resting metabolism, fuel use, cardiorespiratory fitness, and training zones.
Testing is available through scheduled locations, pop-ups, and partner events.
What is metabolic breath testing?
Metabolic breath testing measures the oxygen you take in and the carbon dioxide you breathe out.
Those measurements help estimate how your body is producing and using energy — either while you are resting quietly or while you are exercising at increasing intensity.
Resting metabolic testing can help show:
- How much energy your body uses at rest
- Whether your measured metabolism is higher or lower than predicted
- Whether you are relying more on fat or carbohydrate for fuel at rest
- How your basic energy needs compare with your current nutrition goals
VO₂ testing can help show:
- How much oxygen your body can use during hard exercise
- Your cardiorespiratory fitness level
- Individualized heart-rate and training zones
- How your body uses fuel at different exercise intensities
- A baseline you can retest after a training, nutrition, or health phase
The Science
The mask measures the oxygen you breathe in and the carbon dioxide you breathe out. From that, the system can estimate how your body is producing and using energy. At rest, that can help show your resting metabolic rate and fuel use. During exercise, it can help show your cardiorespiratory fitness, training zones, and how your body responds as intensity increases. In plain English: instead of relying on formulas or wearable estimates, you get data based on your actual breathing.
Choose your test
Resting Metabolic Rate
Choose RMR testing if you want to understand how much energy your body uses at rest and how that compares with an estimated metabolism. This is a good starting point if you are working on nutrition, body composition, under-fueling, weight-management, metabolic health, or a baseline before making changes.
VO₂ Max Testing
Choose VO₂ testing if you want to understand your cardiorespiratory fitness, aerobic capacity, training zones, and how your body uses oxygen during exercise. This is a good fit if you are training for performance, rebuilding fitness, tracking healthy aging, or want more precise information than a wearable or age-based formula can provide.
Midlife Metabolism Audit
Choose the Midlife Metabolism Audit if you want resting metabolic testing placed inside a broader conversation about menopause symptoms, hormones, labs, nutrition, strength, recovery, and next steps.
Resting Metabolic Rate (RMR) — $125
Your resting metabolic rate is the amount of energy your body uses at rest before exercise, errands, work, stress, or the general chaos of being a person gets added on top.
Online calculators estimate this number from population averages. Breath testing measures it from your actual oxygen consumption and carbon dioxide production while you rest.
RMR testing can help you understand:
- Your measured resting energy needs
- How your measured metabolism compares with a predicted estimate
- Whether your body is relying more on fat or carbohydrate for fuel at rest
- Whether your current intake may be low, high, or mismatched for your goals
- A baseline you can retest after a meaningful change in nutrition, training, body composition, recovery, or health
This option includes the resting test and a standard electronic report. Personalized hormone, nutrition, supplement, or full health recommendations are not included.
VO₂ Max Testing — $195
VO₂ max is the maximum amount of oxygen your body can use during hard exercise. It is often talked about in athletic settings, but it is not only an athlete number.
VO₂ max reflects cardiorespiratory fitness — how well your lungs, heart, blood vessels, and working muscles deliver and use oxygen. It can be useful for performance, training, endurance, healthy aging, and tracking whether your fitness is actually improving over time.
During the test, exercise intensity increases gradually while the mask measures your breathing and gas exchange.
VO₂ testing can help you understand:
- Your VO₂ max or peak oxygen uptake
- Individualized heart-rate and training zones
- How your body uses fat and carbohydrate at different exercise intensities
- Ventilatory thresholds and breathing efficiency
- A baseline for performance, fitness, and future retesting
This is a fitness and wellness assessment, not a diagnostic cardiac stress test. People with known or suspected heart or lung disease, unexplained chest pain, fainting, or significant exercise symptoms should be evaluated medically before participating.
What to expect
Before testing, you’ll complete a short health and readiness screening so we can confirm the right test and identify any safety concerns.
During the appointment, you’ll wear a fitted mask connected to the portable analyzer. The mask allows the system to measure your breathing and gas exchange while you rest or exercise.
For RMR testing
You’ll rest quietly while the system measures your breathing. The measurement itself is short, but the full appointment includes setup, mask fitting, calibration, testing, and report delivery.
For VO₂ testing
You’ll exercise on the agreed equipment while intensity gradually increases. The test becomes progressively harder, and you can stop at any time.
Basic preparation
- Avoid food, coffee, nicotine, and other stimulants for at least three hours before testing
- Avoid intense exercise for 24 hours before testing
- Wear comfortable clothing
- Bring athletic shoes for active testing
- Arrive hydrated and early enough to settle before the test
- Follow any additional instructions in your confirmation email
Want to book a test?
Check the current testing schedule to see where Jessie is testing next and which appointments are available.
Want to host testing?
If you own or manage a gym, studio, clinic, office, retreat, or wellness space, you can request a testing day for your members, clients, employees, or guests.
Which test should I choose?
Choose RMR if you want to understand:
- Measured resting calorie needs
- Under-fueling, over-restriction, or a mismatch between intake and goals
- Baseline metabolism before or after a nutrition or strength phase
- Fuel use at rest
Choose VO₂ max if you want to understand:
- Cardiorespiratory fitness and aerobic capacity
- Training zones based on your physiology rather than a generic formula
- Performance, endurance, and exercise efficiency
- A repeatable marker for fitness and healthy aging
Choose the Midlife Metabolism Audit if:
You want the breath data placed inside a wider conversation about menopause symptoms, hormones, labs, nutrition, strength, and next steps.
Better data makes better decisions easier.
Whether you want to understand your resting metabolism, measure your cardiorespiratory fitness, dial in your training zones, or get a clearer baseline before your next health or fitness phase, metabolism and VO₂ testing can help you stop guessing.
Book a standalone test, find an upcoming testing location, or bring testing to your gym, studio, clinic, office, retreat, or event.