What does your VO2max say about how fast you are ageing?
A higher VO2max is strongly associated with lower mortality and a more favourable biological age, but is more of a gauge of your lifestyle than an independent switch for longevity. Reducing body fat and moving more, including gently, delivers the greatest health benefit.
A higher VO2max, the maximum amount of oxygen your body can process per minute during exercise, is one of the strongest known predictors of how long you will live. People in the highest group demonstrably live longer than people in the lowest group. That association has been shown consistently and convincingly1,2.
Yet VO2max is more of a mirror than a switch. A study better able to distinguish cause and effect than ordinary observational research found no evidence that a genetically higher VO2max extends lifespan by itself3. More body fat lowers VO2max causally and substantially. More physical activity raises it causally. VO2max therefore mainly reflects your lifestyle and body composition.
The link with biological ageing is measurable and interesting. An epigenetic clock, a measurement that estimates how fast you are ageing biologically based on DNA patterns, shows the strongest association with VO2max of all clocks examined: every unit of biological ageing acceleration is on average accompanied by a 1.17 mL/kg/min lower VO2max4. This association is observational, so the direction of causality remains unclear.
Training improves your VO2max and adds functional, healthy years, but according to current understanding does not extend the genetically determined maximum lifespan. And light activity already counts. In older women, one extra hour of light activity per day was associated with 22 percent lower mortality and 30 percent fewer cardiovascular events5. For someone with a low VO2max, gentle walking already represents a relatively substantial effort that yields health benefits.
At the gene level there are indications that a variant in the SIRT1 gene is associated with a higher VO2max and greater endurance capacity, but this did not reach a strict statistical threshold and currently has little practical significance6. A review article further describes that exercise may have a favourable effect on the pace of ageing through improved functioning of the energy centres in your cells and reduced chronic inflammation, but that remains a hypothesis without a direct causal test7.
Based on two large studies on VO2max and mortality (PMID 29293447, 38428731), one study distinguishing cause and effect (PMID 38864459), one study on epigenetic clocks and VO2max (PMID 40814797), one study on relative intensity in older women (PMID 38699999), one genetic association study on SIRT1 (PMID 36980932), and one narrative review article (PMID 41683337).