“Zone 2 cardio is the best exercise for longevity”

## The Evidence Zone 2 (60–70% max heart rate, the level where you can still converse) stimulates mitochondrial biogenesis, improves fat oxidation efficiency, and lowers cardiovascular risk. Peter Attia and Iñigo San Millán have popularised this evidence base. However, a 2022 meta-analysis in *BMJ* (Zhao et al.) found resistance training independently reduces all-cause mortality by ~15%, comparable to aerobic training. The strongest evidence comes from combined protocols. ## What the Research Actually Shows The "longevity zone" concept from elite sport research shows that top endurance athletes spend ~80% of training time in Zone 2 and ~20% in high-intensity zones. This principle, exported to general health, has been somewhat overfit — the research population was elite athletes, not sedentary adults seeking longevity. ## The Practical Answer Include 150–200 min/week of Zone 2, 2 sessions of resistance training, and occasional VO2max intervals (the single biggest predictor of longevity in cardiorespiratory fitness data).