VO2 max and longevity: the fitness number most linked to a longer life

VO2 max, the maximum rate at which your body can take in and use oxygen, is one of the strongest single predictors of how long you are likely to live. In a Cleveland Clinic study of 122,007 patients, people with the highest cardiorespiratory fitness had an 80 percent lower risk of dying during follow-up than the least fit, and being unfit carried as much risk as smoking or diabetes. Unlike your genes or your age, it is a number you can move.

That makes it an unusually useful metric for a founder. It is measurable, it responds to training, and it sits upstream of a lot of what you care about: energy in the afternoon, resilience in a hard quarter, and the odds of being around to enjoy whatever comes after the company.

What is VO2 max, in plain terms?

When you work hard, your muscles need oxygen. Your lungs bring it in, your heart pumps it out through the blood, and your muscles extract and use it. VO2 max is the ceiling on that whole chain: the most oxygen your body can process per minute, usually expressed in milliliters per kilogram of body weight per minute.

Researchers often use a related term, cardiorespiratory fitness (CRF). The most precise way to measure it is a lab test where you run or cycle to exhaustion while a mask analyzes your breathing. Many large studies, including the one this post is built on, estimate it from how hard you can work on a treadmill test, recorded as metabolic equivalents, or METs.

The number matters because it is an integrated readout. A high VO2 max means your heart, lungs, blood vessels and muscles are all doing their jobs well. A low one can reflect weakness anywhere in the chain.

What did the landmark Cleveland Clinic study find?

In 2018, Kyle Mandsager, Wael Jaber and colleagues at Cleveland Clinic published one of the largest studies ever done on fitness and mortality. They looked at 122,007 patients who took an exercise treadmill test between 1991 and 2014, then followed them for a median of 8.4 years, covering 1.1 million person-years of observation. During that time, 13,637 patients died.

The researchers sorted everyone into five groups based on fitness compared with others of the same age and sex: low (below the 25th percentile), below average (25th to 49th), above average (50th to 74th), high (75th to 97.6th), and elite (97.7th percentile and above).

Three findings stand out.

The gap between the fittest and least fit was enormous. Elite performers had an adjusted hazard ratio of 0.20 compared with low performers. In the words of the Cleveland Clinic announcement, that is an 80 percent reduction in mortality risk.

There was no ceiling. Even elite performers did better than high performers (adjusted hazard ratio 0.77). The authors concluded that "cardiorespiratory fitness is inversely associated with long-term mortality with no observed upper limit of benefit." That held for patients 70 and older (adjusted hazard ratio 0.71 for elite versus high) and for patients with hypertension (0.70).

Low fitness looked like a major risk factor. This is the part that should get a founder's attention.

Being unfit carried as much risk as smoking

The study compared the risk tied to reduced fitness with the risk tied to conditions every physician already screens for. Moving from above-average to below-average fitness was associated with the same increase in mortality risk as smoking, and more than coronary artery disease.

The paper describes the mortality risk from reduced fitness as "comparable to or greater than traditional clinical risk factors." Most founders know their blood pressure and whether they smoke. Very few know where their fitness sits, even though in this data it mattered about as much.

Senior author Wael Jaber put the practical point simply: "Aerobic fitness is something that most patients can control."

Why fitness belongs on the dashboard

This is not a one-study story. In 2016, the American Heart Association published a scientific statement, led by Queen's University professor Robert Ross, arguing that cardiorespiratory fitness should become a clinical vital sign. The authors recommended that CRF "be measured in clinical practice to provide important information for patient care," and noted that routine estimation is "no more difficult than measuring blood pressure." The statement also linked higher fitness with better outcomes for dementia, depression, type 2 diabetes, surgical risk and certain cancers.

Think about how you run the company. You would not manage revenue by feel, or ignore burn until the bank called. Yet most executives manage their own physical capacity with no leading indicator at all, until a stress test, a scare, or a flight of stairs that feels harder than it did last year.

VO2 max is that leading indicator. It changes slowly enough to reflect real habits and quickly enough to reward a few months of consistent work.

What the evidence says, and what it doesn't

Strong: Across a very large cohort with objective treadmill testing and long follow-up, higher cardiorespiratory fitness was consistently associated with lower mortality, with a graded relationship and no observed upper limit. This matches decades of earlier fitness research, which is why the AHA argued for measuring it routinely.

Important limits: The Cleveland Clinic study is observational. It shows that fit people died less often, not that raising your own fitness will extend your life by a specific amount. Fitter people may differ in other ways, such as genetics, income or other health habits, although the analysis adjusted for many clinical factors. Fitness was measured once, so the study cannot say how changes over time affected risk.

Population caveat: These were patients referred for treadmill testing at a major medical center, many of whom had symptoms or risk factors. The findings may not translate exactly to healthy people who have never been referred.

Measurement caveat: Fitness was estimated from peak METs on a treadmill, not measured directly with gas analysis. Consumer wearable estimates are less precise still. Use them to watch trends, not to compare yourself with a study group to the decimal.

Not supported: Specific claims that a given VO2 max number adds a set number of years, or that any supplement or device raises VO2 max in place of training.

If you have chest pain, shortness of breath out of proportion to effort, a known heart condition, or other chronic conditions, talk with your physician before starting vigorous exercise. The AHA says the same: people with chronic conditions should talk with a healthcare provider about what types and amounts of activity are right before making big changes.

How founders can raise VO2 max this week

None of this requires a coach, a lab or a new gadget to start. It requires consistency, which for most executives is the hard part.

Hit the baseline first. The AHA recommends at least 150 minutes a week of moderate aerobic activity or 75 minutes of vigorous activity, plus muscle strengthening on at least two days. It adds that you can "gain even more benefits by being active at least 300 minutes (5 hours) per week." If you are nowhere near 150, that is the whole plan for now.

Build a base of easy aerobic work. Most of your minutes should feel conversational: brisk walking, easy cycling, an easy jog, rowing. This is sustainable during a fundraise, it improves sleep for many people, and it does not add stress to a system that already has plenty. Walking one-on-ones count.

Add a small dose of hard work. Once a base is in place, many people add one or two sessions a week with short, hard efforts and easy recovery between them. Harder intervals push the ceiling. Keep them brief and build gradually, and check with your physician first if you have any cardiac history.

Get a baseline number. Ask your physician whether a treadmill test or cardiopulmonary exercise test makes sense for you, or use a wearable estimate as a rough starting point. Retest every few months. What gets measured gets protected on the calendar.

Protect the time like a board meeting. Put sessions on the calendar in advance, at a time your week rarely eats (early mornings work for many founders). The most effective program is the one that survives your worst week.

Mind recovery. Fitness gains happen during recovery, and recovery depends on sleep. If you are sleeping five hours and training hard, most of what you add is load, and the capacity gains stall. Our post on meditation for sleep for executives covers a practical wind-down.

Fitness, stress and the nervous system

There is a reason cardiorespiratory fitness shows up in research on depression and cognitive decline as well as heart disease. Aerobic training trains your stress physiology too: you raise your heart rate, mobilize energy, and then recover. Over time, people often find their resting heart rate drops and they bounce back faster from hard days. We look at what chronic stress does to that system in what chronic stress does to a founder's body.

That is also where meditation work fits. Training capacity on the bike and training the ability to downshift in the chair are two sides of the same skill: moving between effort and recovery on purpose instead of staying half-activated all day. At Cinder, private 1:1 coaching focuses on the second half, stress regulation and attention, fitted to a real executive calendar and complementary to the training and medical care you already have. Our piece on meditation for CEOs and decision-making shows how that shows up at work.

Treat your fitness like a lead indicator

The Cleveland Clinic data makes a blunt case: among the risk factors you can influence, few are as strongly tied to how long you live as how fit you are. Get a baseline, hit the weekly minimum, add a little intensity when you are ready, recover properly, and retest. Then keep going, because in this data the benefit did not top out.

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Sources

• Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing, JAMA Network Open, 2018
• Cleveland Clinic research shows better cardiorespiratory fitness correlates to a longer life, Cleveland Clinic, 2018
• Researchers author scientific statement for American Heart Association, recommending fitness become clinical vital sign, University of South Carolina, 2016
• American Heart Association recommendations for physical activity in adults and kids, American Heart Association, 2024