The best-evidenced longevity intervention is exercise, and most of it is cheap

The intervention with the strongest evidence for a longer life is not sold in a bottle. Across cohorts totalling well over a million people, regular physical activity is associated with roughly a third lower risk of dying over follow-up, an effect no anti-ageing supplement or drug has come close to demonstrating in humans [s1][s3]. The two findings that matter most for a reader are that most of the benefit arrives at a modest, achievable dose, and that doing far more does not keep buying proportionally more life [s1][s2].

This is observational evidence — people who exercise differ from people who do not in ways that inflate the apparent benefit — so the numbers below are associations, not a measured causal dose. But the consistency across enormous, independent cohorts, and the biological plausibility, make physical activity the best-evidenced lever in the whole longevity field, precisely the standing that no geroprotector pill has earned.

The dose-response curve bends early

The clearest map of the curve comes from a pooled analysis of six US and European cohorts: 661,137 adults with 116,686 deaths over a median 14.2 years of follow-up [s1]. Compared with reporting no leisure-time activity, people doing even less than the recommended minimum of 7.5 metabolic-equivalent (MET) hours a week had a 20% lower mortality risk (hazard ratio 0.80, 95% CI 0.78 to 0.82); at one to two times the minimum the risk was 31% lower (HR 0.69, 0.67 to 0.70), and at two to three times, 37% lower (HR 0.63, 0.62 to 0.65) [s1]. The benefit then flattened: an upper threshold sat at three to five times the recommendation (HR 0.61, 0.59 to 0.62), only modestly better than meeting it [s1]. Crucially, there was no sign of harm at the extreme — even at 10 or more times the minimum, mortality was still lower (HR 0.69, 0.59 to 0.78) [s1]. The same dose-response shape held for both cardiovascular and cancer mortality, and the extra benefit of pushing to the upper threshold rather than simply meeting the guideline was modest [s1].

A 2023 dose-response meta-analysis put a sharper point on where the curve bends. Pooling 196 articles covering 94 cohorts and more than 30 million participants, it found the steepest gains between doing nothing and 8.75 marginal MET-hours a week — the equivalent of the recommended 150 minutes of moderate activity — with smaller marginal gains above that [s3]. At that 8.75-hour level the relative risk was 0.69 (95% CI 0.65 to 0.73) for all-cause mortality, 0.71 (0.66 to 0.77) for cardiovascular death and 0.85 (0.81 to 0.89) for cancer death [s3]. The authors estimated that if every insufficiently active adult reached that level, 15.7% of premature deaths (95% CI 13.1 to 18.2) would be averted [s3].

Intensity and the plateau

A 30-year US cohort of 116,221 adults, with 47,596 deaths, tested how far up the intensity ladder the benefit runs [s2]. Meeting the guideline for vigorous activity (75 to 149 minutes a week) was associated with lower all-cause mortality (HR 0.81, 95% CI 0.76 to 0.87) and lower cardiovascular mortality (HR 0.69, 0.60 to 0.78); meeting the moderate-activity guideline (150 to 299 minutes) gave 19% to 25% lower risk of all-cause, cardiovascular and non-cardiovascular death [s2]. The near-maximal association was reached at roughly 150 to 300 minutes a week of vigorous activity or 300 to 600 minutes of moderate activity; going beyond that — 300 or more vigorous minutes, or 600 or more moderate — showed no clear further benefit and, reassuringly, no harm [s2].

What the guidelines ask for

The public-health target these studies validate is deliberately modest. The World Health Organization's 2020 guidelines recommend that all adults do 150 to 300 minutes of moderate-intensity, or 75 to 150 minutes of vigorous-intensity, aerobic activity a week, plus muscle-strengthening activity, with children and adolescents averaging 60 minutes a day [s4]. The cohort data suggest a reader worried about ageing gets the bulk of the mortality benefit simply by clearing — or even approaching — that bar, not by chasing ever-higher volumes [s1][s3].

The strength side of the ledger carries its own mortality signal: resistance training shows its own dose-response for death, and preserving muscle is central to what actually works against ageing muscle. Set against a longevity market selling unproven pills, the evidence here is unusual for being both strong and free.