Fitness and Life Expectancy: What Two Million People Tell Us About Living Longer
Updated: 4 days ago
People ask how long they will live as if the answer were fixed at birth. A large part of it is, and a large part is not. Among the modifiable factors, the ones with the strongest and most consistent relationship to mortality are how fit you are and how much you move, and both have now been measured across millions of person-years.
The evidence
The evidence comes from a 2022 updated meta-analysis in Mayo Clinic Proceedings of 37 cohort studies and more than 2.2 million participants on objectively measured cardiorespiratory fitness and all-cause mortality (Laukkanen, Isiozor and Kunutsor 2022), and a 2022 meta-analysis in The Lancet Public Health of 15 international cohorts and 47,471 adults on daily step counts and mortality (Paluch and colleagues 2022).
What happened
Across 108,613 deaths, people in the highest third of cardiorespiratory fitness had about 45 percent lower all-cause mortality than those in the lowest third (relative risk about 0.55). Each additional MET of fitness capacity was associated with about 11 percent lower risk. The authors described the association as strong, inverse and independent of other risk factors and recommended fitness be assessed routinely in clinical risk evaluation.
In the step-count analysis, over a median seven years, mortality fell steadily with more daily steps: compared with the least active quarter, risk was about 40 percent lower in the second quarter, 45 percent lower in the third and 53 percent lower in the most active quarter.
The benefit plateaued at roughly 6,000 to 8,000 steps a day for adults aged 60 and over and 8,000 to 10,000 for younger adults. Walking faster added a modest further benefit but did not stand on its own once total steps were accounted for.
Both analyses are observational, so they show association rather than proof of cause, but the dose-response relationships and the size of the effects are among the largest for any modifiable risk factor.
The current answer
Fitness and activity are two of the strongest predictors of how long a person lives, and unlike age, sex and family history they can be changed. Moving from unfit to fit is associated with cutting the risk of death in a given period roughly in half, and every step up in fitness capacity counts, with no upper limit identified in the pooled data. Everyday movement matters independently: the difference between 3,000 and 8,000 steps a day is associated with about a 50 percent lower mortality risk, and beyond 8,000 to 10,000 steps the curve flattens. Sedentary time, smoking and weight history all matter as well, but the sources here address fitness and movement, and on those two the message is unambiguous.
How certain is this?
High for the strength and consistency of the associations, which come from very large cohorts with objective measurements and clear dose-response gradients. Moderate for causality, since cohort studies cannot fully exclude reverse causation, though the persistence of the associations after adjustment and in healthy subgroups makes a causal contribution likely.
Fitness is the one risk factor for early death that you can change in a season. Every MET you add buys about a tenth off the risk.
What this means in practice
Treat cardiorespiratory fitness as a health number worth knowing: a field test such as a timed walk or run, or a submaximal test, gives an estimate in METs that can be tracked over time.
Aim to add fitness rather than just activity: two to three sessions a week of aerobic work hard enough to raise fitness, on top of daily movement, is what moves the MET figure.
Set a daily step floor of about 7,000 to 8,000 steps for most adults and 6,000 to 8,000 past 60, and treat anything above 10,000 as a bonus rather than a requirement.
Do not let the plateau discourage effort: the steepest gains in the data came from moving the least active people to moderate activity, which is where most of the population sits.
Combine the two: a fitter person who also walks more sits at the bottom of every risk curve in these analyses.
Ohana Performance Institute builds programmes that raise measured fitness and daily movement together, because those two numbers carry more weight for long-term health than almost anything else a person controls. If you want a plan aimed at both, a coaching consultation is where to start.
References
Laukkanen JA, Isiozor N, Kunutsor SK. Objectively Assessed Cardiorespiratory Fitness and All-Cause Mortality Risk: An Updated Meta-Analysis of 37 Cohort Studies Involving 2,258,029 Participants. Mayo Clinic Proceedings. 2022. https://doi.org/10.1016/j.mayocp.2022.02.029
Paluch AE, Bajpai S, Bassett D, Carnethon M, Ekelund U, et al. Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts. The Lancet Public Health. 2022. https://doi.org/10.1016/S2468-2667(21)00302-9
Last reviewed: 4 September 2026. Re-review when a new pooled analysis of fitness or step counts and mortality is published, or by September 2028.
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