What Longevity Actually Means

Longevity is often reduced to a single number. In research, the more useful framing is healthspan: the period of life spent with good physical and cognitive function. That framing brings several measurable domains into view — cellular and mitochondrial function, metabolic health, recovery capacity, physiological resilience, and markers of biological rather than chronological age. It also puts the foundations back where the evidence is strongest: sleep, nutrition, physical activity, muscle mass, cardiorespiratory fitness and metabolic control. Emerging research on molecular pathways is genuinely interesting, but it sits on top of those foundations rather than replacing them.