How Does VO2 Max Predict Longevity and How Can It Be Improved?

The short answer

VO2 max — the maximum rate at which the body can consume oxygen during exercise — is the strongest known predictor of all-cause mortality. Mandsager et al. (2018) found that elite fitness (top 2.5% of VO2 max for age) was associated with a 5-fold lower mortality risk compared to low fitness — a larger effect than any other modifiable risk factor studied. Each 3.5 mL/kg/min increase in VO2 max is associated with a 13% lower mortality risk.

What the evidence actually shows

Mandsager et al. (2018) in JAMA Network Open analysed 122,007 patients who underwent exercise treadmill testing and found that low cardiorespiratory fitness (CRF) was associated with higher mortality than smoking, hypertension, diabetes, or end-stage renal disease. The mortality risk gradient was steep: elite CRF was associated with a 5-fold lower mortality risk than low CRF. Kodama et al. (2009) in JAMA, pooling 33 studies and 102,980 participants, found that each 3.5 mL/kg/min increase in CRF was associated with a 13% lower all-cause mortality risk and a 15% lower cardiovascular mortality risk.

"Low cardiorespiratory fitness was associated with higher mortality than smoking, hypertension, diabetes, or end-stage renal disease."

— Mandsager et al., JAMA Network Open 2018

What the major health authorities say

The NIA identifies cardiorespiratory fitness as a key component of healthy ageing and recommends regular aerobic exercise to maintain and improve it. The American Heart Association has called for CRF to be recognised as a clinical vital sign, recommending routine assessment in clinical practice. The NIA notes that VO2 max declines by approximately 10% per decade after age 30, but that regular aerobic training can substantially slow this decline.

Practical implications

VO2 max can be estimated without laboratory testing using submaximal exercise tests (Cooper 12-minute run test, Rockport walking test) or from wearable devices (Apple Watch, Garmin, Polar). The most effective interventions for improving VO2 max are: high-intensity interval training (HIIT) — 2–3 sessions per week of intervals at 85–95% of maximum heart rate; Zone 2 training — sustained aerobic exercise at 60–70% of maximum heart rate for 150+ minutes per week; and progressive overload — gradually increasing exercise intensity and duration over months.

Where reasonable people still disagree

• Whether the mortality benefit of high VO2 max is causal (high fitness protects health) or reflects reverse causation (healthier people naturally achieve higher fitness).
• The relative merits of HIIT versus Zone 2 training for improving VO2 max and longevity outcomes in older adults.
• Whether there is a point of diminishing returns or even harm from very high exercise volumes for VO2 max and cardiovascular health.