VO₂ max and longevity: the number you can actually change

VO₂ máx y longevidad: el número que sí puedes cambiar

Your body has a number that predicts how long you will live better than your cholesterol, better than your blood pressure, and better than whether you smoke. It is called VO₂ max, and unlike your age or your genes, you can change it.

It is the maximum amount of oxygen your body can use when you push hard. It measures how well your lungs, heart, blood and muscles work together. In a single figure, it is the size of your engine.

And that is the good news in this article: of all the things that predict how long you live, this is one of the few that is in your hands.

What VO₂ max actually is

Picture your body as a car. VO₂ max is not the fuel or the tank. It is the size of the engine.

Technically it is the maximum volume of oxygen you can consume per minute, adjusted for your body weight. It is measured in milliliters of oxygen per kilogram per minute.

For that number to be high, several things have to work well at once: your lungs taking in oxygen, your heart pumping blood with force, your vessels carrying it, your blood transporting it, and your muscles — specifically their mitochondria — using it.

That is why it predicts so well. It does not measure one organ. It measures the whole system working together.

If you have read our articles on MOTS-c and the mitochondria or on SS-31, this is where it all connects: VO₂ max is, to a large degree, the measurable real-world expression of how well your mitochondria are working.

The 122,000-person study

In 2018, Cleveland Clinic researchers published in JAMA Network Open one of the largest analyses that exists on this question.

They followed 122,007 adults who had undergone treadmill exercise testing between 1991 and 2014. Median follow-up was 8.4 years, covering 1.1 million person-years, with 13,637 deaths recorded.

Participants were sorted into five fitness groups, always compared against people of the same age and sex: low, below average, above average, high and elite.

The risk-adjusted result was stark. Compared with the elite group, the low-fitness group had an all-cause mortality risk 5.04 times higher (95% confidence interval: 4.10 to 6.20).

The comparison that surprises people

The striking part is not that number alone, but what the authors placed beside it. In the same analysis they measured the risk tied to the classic risk factors:

• Coronary artery disease: adjusted risk 1.29 times higher.
• Smoking: 1.41 times higher.
• Diabetes: 1.40 times higher.
• Being below average in fitness (compared with above average): 1.41 times higher.

Read that again. Being below average in aerobic capacity was associated with the same increase in risk as smoking.

And unlike your genes, this one is trainable.

No ceiling: more is better

For years there was a circulating idea that too much endurance exercise might be bad for the heart. This study was designed in part to answer that.

The authors' conclusion was clear: cardiorespiratory fitness was inversely associated with mortality with no observed upper limit of benefit. Even the elite group had lower risk than the high group (adjusted risk 0.77 — that is 23% lower).

And the advantage of elite over high also showed up in two subgroups where you might expect the opposite: people aged 70 or older, and people with hypertension.

That matters a great deal if you are over 60 and think it is too late. The data say otherwise.

The best part: you can change it

A high number is one thing. Being able to raise it is another, and that is what decides whether this article is any use to you.

The HUNT study in Norway followed 30,375 people whose aerobic fitness was estimated twice, ten years apart. Those data were then linked to national dementia and mortality registries.

They compared four trajectories: unfit at both assessments, improved, declined, and fit at both.

Compared with those who stayed unfit at both assessments, people who improved their fitness over those ten years had a 48% lower risk of developing dementia (adjusted hazard ratio 0.52) and a 28% lower risk of dementia mortality.

And the authors translated it into the unit people actually understand: those who improved gained 2.2 dementia-free years and 2.7 years of life compared with those who stayed the same.

Every unit of improvement counted. For each metabolic equivalent gained, dementia risk fell by 16%.

They did not need to reach elite. They needed to move from where they were.

And not just the brain

In a Finnish study that measured VO₂ max directly with respiratory gas analysis on two occasions eleven years apart, each milliliter per kilogram per minute of improvement was associated with a 10% lower risk of heart failure.

How it is measured (and how to estimate it without a lab)

The exact measurement is done in a laboratory: a treadmill or bike, a mask analyzing the air you exhale, and a test that ramps up in intensity to your limit. It is called a cardiopulmonary exercise test.

Most people do not need that. There are reasonable ways to locate yourself:

• Your watch or band. Many estimate VO₂ max from pace and heart rate. It is not exact, but it works well for seeing whether your number rises or falls over months.
• The talk test. If you can walk briskly and speak in full sentences but not sing, you are at moderate intensity. It is a practical, free marker.
• Stairs. Climbing two or three flights at a steady pace without stopping is an informal reference many clinicians use.
• A clinical exercise test, if your physician considers it appropriate given your history.

The American Heart Association published a scientific statement in Circulation asking for exactly this: that aerobic fitness be assessed in clinical practice as a vital sign alongside blood pressure and pulse. Their argument was that adding it to traditional risk factors significantly improves risk prediction.

What matters is not the absolute number. It is the direction it is moving.

How to raise it, concretely

Here is the actionable part, and it is simpler than it looks.

The base: volume at a comfortable intensity

Most of your weekly movement should be at an intensity where you can hold a conversation. Brisk walking counts, and it counts more than people think. Aim to accumulate time, not to suffer.

The stimulus: intervals, short and sharp

VO₂ max responds especially to working near your ceiling. That means short bouts of hard effort where you can no longer talk, followed by recovery.

You do not need to run. A hill walked fast, a stationary bike, the stairwell in your building or a pool all work. What matters is that your body ends up asking for air.

Strength counts too

More muscle mass means more mitochondria working and a better ability to sustain effort. It also protects against age-related muscle loss. We have a dedicated article on strength training while losing weight.

Sleep is not optional

Adaptation to training happens while you rest, not while you train. If you sleep badly, you train and do not improve. We cover it in sleep and weight.

Start below what you think you can do

The most common mistake is not training too little. It is starting too hard, feeling awful, and quitting in three weeks. Months of consistency beat any heroic session.

What a realistic week looks like

You do not need a complicated plan. A structure that works for most people starting out:

• Three or four conversational-pace sessions of 25 to 40 minutes. Brisk walking counts. This is where the base is built.
• One session with some intensity: four to six repeats of one or two minutes where you are short of breath, with two or three minutes of easy walking between each.
• Two short strength sessions, covering legs, a push and a pull.
• One real rest day. That is not laziness — it is when adaptation happens.

If you do none of this today, do not start with all of it. Start with the walks. Add intensity once the walks are a habit rather than a decision.

The three most common mistakes

One: everything at medium intensity. Not truly easy, not truly hard. It tires you a lot and stimulates little. If you are going easy, go easy. If you are going hard, keep it short.

Two: judging the session instead of the month. One workout does not move your VO₂ max. Three months of consistency does.

Three: dropping protein. If you train and do not repair, you lose muscle — and muscle is part of the engine. This matters even more if you are losing weight.

And if you want the full picture of where this fits among everything said about longevity, start with what longevity really means.

So your expectations are the right ones

Two things, so you read the evidence with a fair balance.

First. The large studies cited here are observational. They show a very strong and consistent association, adjusted for many factors, but on their own they do not prove cause and effect.

Second, and this one matters. The Generation 100 trial, published in the BMJ, randomized 1,567 adults aged 70 to 77 to five years of high-intensity intervals, moderate-intensity training, or following national physical activity guidelines. All-cause mortality was not significantly different between groups. There was a trend favoring intervals, but the confidence interval crossed 1.

Now, the detail that explains that result and is worth not missing: the control group moved too, and a fair amount. At baseline, 80% already reported medium or high physical activity, and they ended up doing more high-intensity work than the group assigned to moderate intensity. This was not exercise versus couch. It was one dose of exercise versus another.

The honest reading is this: the large benefit is in going from sedentary to active, and that is exactly what the cohort studies show. Fine-tuning intensity once you already move is a much smaller argument.

Individual results vary and are not guaranteed.

Who is this NOT for?

If you have known heart disease, chest pain with exertion, fainting or arrhythmias, do not start high-intensity intervals on your own. That is a conversation to have with a physician first, and it may require a supervised exercise test.

If you have uncontrolled hypertension, diabetes with complications, or you have gone years without regular physical activity, progression should be gradual and clinically guided.

If you are pregnant, there are specific recommendations and they are worth following with your obstetrician.

If you have an active injury or significant joint pain, the path is to adapt the type of exercise — bike, water, elliptical — not to push through pain.

And if you are losing weight on a GLP-1, this is especially relevant: protecting muscle and aerobic capacity while you lose weight is part of the work, not an extra. We explain it in strength training while losing weight.

GLP-1 programs with FDA-approved medications (Wegovy®, Foundayo™, Ozempic®) from $149/month, by telemedicine, in Spanish and English

Real clinical oversight, in English and Spanish, with continuous follow-up.

Eligibility is determined by medical evaluation. Individual results vary and are not guaranteed.

Frequently asked questions

What is a good VO₂ max?

It depends on your age and sex, which is why studies always compare within the same group. More useful than chasing a specific figure is knowing what percentile you are in for your age — and above all whether your number is rising or falling over the months.

Is the VO₂ max from my watch any use?

As a rough estimate, yes, and it is very useful for tracking trends. But it is not a direct measurement. A study in the Journal of the American Heart Association found that non-exercise prediction equations correctly classified the direction of change in only 56% of cases, so do not read too much into small swings.

At 65, is it still worth it?

Yes. In the Cleveland Clinic study, the benefit of higher aerobic capacity held in people aged 70 and older. And in the HUNT study, those who improved their fitness over ten years gained years of life and dementia-free years.

How long does it take to see a change?

Changes in aerobic capacity are measured in months, not weeks, and they vary a lot between people. Do not compare yourself to anyone else — compare yourself to you three months ago.

Do I have to run?

No. Any activity that raises your heart rate in a sustained way counts: walking uphill, cycling, swimming, stairs, rowing. The best one is the one you can keep doing for years.

Can I improve my aerobic capacity while losing weight on a GLP-1?

That is a conversation for your physician, because it depends on your case. In general, maintaining physical activity and adequate protein during weight loss is part of the plan, not an optional add-on.

Do supplements raise VO₂ max?

None replace training. What raises aerobic capacity consistently and measurably is the stimulus of sustained exercise over time.

Sources

• Mandsager K, et al. Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Netw Open. 2018;1(6):e183605. — DOI · via PubMed
• Tari AR, et al. Temporal changes in cardiorespiratory fitness and risk of dementia incidence and mortality: a population-based prospective cohort study (HUNT). Lancet Public Health. 2019;4(11):e565-e574. — DOI · via PubMed
• Ross R, et al. 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. 2016;134(24):e653-e699. — DOI · via PubMed
• Stensvold D, et al. Effect of exercise training for five years on all cause mortality in older adults — the Generation 100 study: randomised controlled trial. BMJ. 2020;371:m3485. — DOI · via PubMed
• Khan H, et al. Long-Term Change in Cardiorespiratory Fitness in Relation to Atrial Fibrillation and Heart Failure (Kuopio Ischemic Heart Disease Risk Factor Study). Am J Cardiol. 2018;121(8):956-960. — DOI · via PubMed
• Peterman JE, et al. Accuracy of Nonexercise Prediction Equations for Assessing Longitudinal Changes to Cardiorespiratory Fitness in Apparently Healthy Adults. J Am Heart Assoc. 2020;9(11):e015117. — DOI · via PubMed

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This article is informational and is not medical advice. SCTS1 does not prescribe medication. All medical care, prescriptions and treatment plans are provided by licensed physicians through our partner platform, and preparations are dispensed by licensed pharmacies. Eligibility is determined by a licensed provider. Before starting a high-intensity exercise program, especially if you have a known cardiovascular condition, consult a licensed physician. Individual results vary and are not guaranteed.