Home Breath Testing: A Mask That Reads Your Metabolism

A mask that measures the oxygen you consume and the carbon dioxide you exhale can tell you, with real precision, how hard your body can work and what fuel it is burning. On September 26, 2026, PNOĒ announced a self-serve version of exactly that, running a full test in about eight minutes. Home breath testing is the obvious next step, and it is also the part of the story that is not true yet: the company sells to businesses, not households, at $400 to more than $1,000 a month. Understanding why is more useful to a family than the launch itself.

Key Takeaways

• PNOĒ’s new mask captures 23 biomarkers in roughly eight minutes, including VO₂ max, resting metabolic rate and metabolic flexibility. It launched October 1, 2026.
• It is not cleared by the U.S. Food and Drug Administration and is classified as a wellness device, which legally limits what it may claim.
• The measurement principle is indirect calorimetry: oxygen in, carbon dioxide out, and arithmetic. That is genuinely teachable at a kitchen table.
• Cardiorespiratory fitness matters. A 2016 American Heart Association scientific statement argued it should be treated as a clinical vital sign and can predict mortality better than smoking or hypertension.
• The gap this fills is real: WHO reported in June 2024 that 81% of adolescents aged 11 to 17 were physically inactive, with girls at 85% and boys at 78%.

What PNOĒ announced, and what it actually sells

Metabolic testing is the measurement of how much oxygen a body uses and how much carbon dioxide it produces, in order to calculate energy expenditure and fuel use. TechCrunch covered the launch on September 26, 2026, with the product going live on October 1.

The hardware detail that makes self-serve possible is mundane and clever. The electronics detach from the silicone mask and straps, so several people can share the expensive part while each keeps their own mask. A test takes about eight minutes and produces 23 biomarkers.

Now the parts that get skipped in coverage. The company sells exclusively to businesses. Subscriptions run from $400 a month to more than $1,000, covering hardware, software, training and marketing material. Clients include Equinox, Four Seasons hotels, the NBA and Mount Sinai Health System. PNOĒ was founded ten years ago by Apostolos Atsalakis and Panos Papadiamantis, is based in Malden, Massachusetts with operations in Athens, has raised about $22 million, and recently became profitable with growth above 100% a year. Roughly 85% of revenue comes from the United States.

So “lab tests move into the home” is directionally right and literally premature. What moved is the operator: the test no longer needs a technician standing over you. Whether the mask ends up in a house or stays in a gym depends on price, and price depends on whether a consumer version is ever built.

How a breath test actually works

This is chemistry a twelve-year-old can follow, and it is worth following because it demystifies the number.

Your cells burn fuel using oxygen and release carbon dioxide. If you capture everything a person breathes out and compare it with what they breathed in, two quantities follow directly: how much oxygen disappeared, and how much carbon dioxide appeared. The technique is called indirect calorimetry, because it calculates heat production without measuring heat.

From those two numbers you get the useful ones:

VO₂ max is the highest rate of oxygen consumption a body can sustain, usually expressed in millilitres of oxygen per kilogram of body weight per minute. It is a ceiling on aerobic work.

Resting metabolic rate is energy burned at rest, derived from oxygen consumption while sitting still. This is the number most people guess wrong about themselves, often by hundreds of calories.

Metabolic flexibility is the ratio of carbon dioxide produced to oxygen consumed, called the respiratory exchange ratio. Burning pure carbohydrate produces about one molecule of CO₂ per molecule of O₂. Burning fat produces about 0.7. So a ratio near 1.0 means carbohydrate, near 0.7 means fat, and the ability to shift between them is what “flexibility” names.

No machine learning is required for any of that. It is gas analysis and division. The AI framing on these products usually refers to how the results are presented, not how they are measured.

What each number is good for, and where it stops

Measurement	How it is derived	Genuinely useful for	Where it stops
VO₂ max	Peak oxygen consumption during graded exercise	Tracking training effect; risk stratification in clinical settings	Highly dependent on effort and motivation on the day
Resting metabolic rate	Oxygen consumption at rest	Correcting bad calorie estimates	Varies with sleep, caffeine, illness and recent meals
Respiratory exchange ratio	CO₂ produced divided by O₂ consumed	Understanding fuel mix during exercise	Not a verdict on diet quality or body composition
Breathing efficiency metrics	Ventilation volume and rate	Spotting inefficient breathing patterns	Easy to over-interpret
Wrist-based “VO₂ max estimate”	Heart rate plus pace, modelled	Rough trend over months	Estimated, not measured; errors compound

That last row is the comparison that matters for most families, because almost nobody is buying a $400-a-month subscription and almost everybody has a watch claiming to know their VO₂ max.

The accuracy gap is documented in adjacent territory. Chinoy and colleagues, writing in Sleep in 2021, compared seven consumer sleep trackers with laboratory polysomnography. Sensitivity for detecting sleep was 0.93 or higher across the board; specificity for detecting wakefulness ran from 0.18 to 0.54. Consumer sensors are decent at coarse states and poor at fine distinctions. Expect the same shape of error from a modelled fitness estimate.

Why fitness measurement is worth caring about anyway

It would be easy to treat all of this as quantified-self theatre. The clinical literature says otherwise.

In 2016, the American Heart Association published a scientific statement led by Robert Ross in Circulation, titled “Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign.” Its core argument: low cardiorespiratory fitness is associated with high risk of cardiovascular disease, all-cause mortality and several cancer mortality rates, and fitness may predict mortality better than traditional risk factors including smoking and hypertension. The statement runs from page e653 to e699, which tells you how much evidence they were summarising.

Against that, the WHO physical activity fact sheet updated June 26, 2024 reports that 81% of adolescents aged 11 to 17 were physically inactive, 85% of girls and 78% of boys. That is the population-level problem no mask solves.

And measurement alone does not solve it either. Au and colleagues, in a 2024 systematic review and meta-analysis in The Lancet Digital Health, pooled 21 randomised trials covering 3,676 young people with a mean age of 13.7 years. Wearable activity trackers produced a significant increase in daily steps, with a standardised mean difference of 0.37 (95% CI 0.09 to 0.65, p=0.013), and no detectable effect on moderate-to-vigorous physical activity (−0.08, 95% CI −0.18 to 0.02, p=0.11). More steps. Not more hard exercise.

How to Teach Your Kid About Home Breath Testing

Ages 5–8: the balloon and the mirror

Breathe on a cold mirror and watch it fog. That water came out of a lung. Then blow up a balloon in one breath, let it go, and blow up a second one after running around the house for two minutes. The second balloon is bigger and arrives faster. Ask: where did the extra air go, and what was your body doing with it? You are teaching that breathing is a measurable thing with a reason.

Ages 9–12: the limewater test for carbon dioxide

Stir a spoon of calcium hydroxide (garden lime) into water, let it settle, and pour off the clear liquid. Blow through a straw into it. It turns cloudy, because carbon dioxide reacts with the calcium hydroxide to form calcium carbonate, which does not dissolve. Then do it again after exercise and compare how many seconds it takes to go cloudy. That is a crude carbon dioxide meter built from garden supplies, and it is the same signal the mask reads with an infrared sensor. Our explainer on how sensors turn physical things into numbers covers the electronic version.

Ages 13+: calculate a fuel ratio from numbers you look up

Give your teenager the respiratory exchange ratio definition and two numbers: CO₂ produced and O₂ consumed, from any published exercise physiology table. Have them compute the ratio and say which fuel dominates. Then have them explain why a ratio above 1.0 is possible during very hard exercise — the answer involves buffering lactic acid and releasing extra CO₂, and working it out is a genuinely satisfying piece of reasoning.

The question to ask: “If this mask only measures two gases, how can it report 23 different numbers?”

The honest answer is that most of the 23 are calculated from the same two measurements plus body weight and time. Recognising that a long results page can come from two sensors is a durable piece of scientific literacy.

What to do at home

Use the free test that already exists

A one-mile walk or a timed shuttle run, done the same way every eight weeks, tracks cardiorespiratory fitness well enough for a family. Write the time on the fridge. No subscription, no account, no data leaving the house. This is the version that actually gets repeated.

Treat any “VO₂ max” on a watch as an index, not a measurement

It is modelled from heart rate and pace. Watch the direction over three months and ignore the absolute number. If your teenager’s figure drops eight points in a week, that is a sensor or a sleep problem, not a physiological collapse.

Ask one question before any paid body test

“What would I do differently if the result came back bad?” If the answer is “exercise more,” you already knew the action and the test is optional. If the answer involves a specific clinical decision, that test should be ordered by a clinician, not bought.

Know what the wellness classification means

A device regulated under the FDA’s general wellness policy for low-risk devices may make claims about maintaining a healthy lifestyle but not about diagnosing, treating, preventing or mitigating disease. That is why these reports talk about “optimisation” rather than diagnosis. It is a legal boundary, and reading marketing copy with it in mind is clarifying.

What not to do

Do not put a metabolic number in front of a child or teenager who is anxious about their body. A resting metabolic rate expressed in calories is an invitation to calorie counting, and the evidence on fitness benefit does not justify that risk. Our review of what the evidence says about health tracking for kids goes into the trade-off in detail.

What to Watch For Over the Next 3 Months

• Week 4: Watch for consumer-priced breath testing appearing in gyms and physiotherapy clinics near you. The business model is monthly subscriptions to operators, so the test shows up where operators are, not in catalogues.
• Month 2 red flags: Any marketing that uses metabolic numbers to sell a diet plan, or that describes a wellness device as diagnostic. Both are signals to walk away, and the second may be a regulatory problem.
• Month 3 self-check: Compare your family’s eight-week walk or run times. If they have improved, the measurement did its job. If no one did the test twice, no device would have changed that.

Frequently Asked Questions

Is this the same as a hospital metabolic test?

The principle is identical: indirect calorimetry using oxygen consumption and carbon dioxide production. The company claims lab-equivalent accuracy. The difference is regulatory and procedural. It is not FDA cleared, it is classified as a wellness device, and there is no clinician interpreting the result.

Can I buy one for my family?

Not at present. PNOĒ sells only to businesses, with subscriptions from $400 to over $1,000 a month that include hardware, software and training. Access comes through a gym, clinic or hotel that has one.

Is my watch’s VO₂ max number real?

It is an estimate derived from heart rate and pace, not a measurement of oxygen. Treat it as a trend line. Consumer sensors, as the 2021 Sleep comparison showed, are reliable at coarse distinctions and unreliable at fine ones.

Should a healthy teenager get a metabolic test?

There is no evidence of benefit for a healthy adolescent, and a plausible psychological cost. Fitness in that age group responds to doing more activity, which the WHO data suggests 81% of 11-to-17-year-olds are not doing. Measuring is not the bottleneck.

What is the best single thing to measure at home?

Time over a fixed distance, repeated. It captures most of what VO₂ max captures for a family’s purposes, costs nothing, and generates no data anyone else can see.

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About the author

Ricky Flores is the founder of HiWave Makers and an electrical engineer with 15+ years of experience building consumer technology at Apple, Samsung, and Texas Instruments. He writes about how kids learn to build, think, and create in a tech-saturated world. Read more at hiwavemakers.com.

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Sources

1. TechCrunch. (2026, September 26). “PNOĒ’s new face mask wants to make lab-grade breath testing a self-serve affair.” TechCrunch. https://techcrunch.com/2026/09/26/pnoes-new-face-mask-wants-to-make-lab-grade-breath-testing-a-self-serve-affair/
2. Ross, R., et al. (2016). “Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association.” Circulation, 134, e653–e699. https://doi.org/10.1161/CIR.0000000000000461
3. World Health Organization. (2024, June 26). “Physical activity.” WHO Fact Sheet. https://www.who.int/news-room/fact-sheets/detail/physical-activity
4. U.S. Food and Drug Administration. (2026, January). “General Wellness: Policy for Low Risk Devices.” FDA Guidance for Industry and FDA Staff. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/general-wellness-policy-low-risk-devices
5. Au, W. W., Recchia, F., Fong, D. Y., Wong, S. H. S., Chan, D. K. C., Capio, C. M., Yu, C. C. W., Wong, S. W. S., Sit, C. H. P., Ip, P., Chen, Y. J., Thompson, W. R., & Siu, P. M. (2024). “Effect of wearable activity trackers on physical activity in children and adolescents: a systematic review and meta-analysis.” The Lancet Digital Health, 6(9), e625–e639. https://doi.org/10.1016/S2589-7500(24)00139-0
6. Chinoy, E. D., et al. (2021). “Performance of seven consumer sleep-tracking devices compared with polysomnography.” Sleep, 44(5), zsaa291. https://doi.org/10.1093/sleep/zsaa291