Cardiorespiratory Fitness as the Primary Determinant of Longevity

Introduction to the Evidence

The American Diabetes Association establishes that cardiorespiratory fitness is the single best determinant for longevity, reducing mortality risk across all categories of body composition and appearing more protective than leanness alone, according to the American Diabetes Association 1

Moderate-to-high cardiorespiratory fitness eliminates elevated mortality risk even in obese individuals, while lean individuals have increased longevity only if they are physically fit, as stated by the American College of Cardiology 1
Physical activity reduces inflammation, which is a predictor of multimorbidity and mobility loss, as per the American Heart Association 1
Physical activity modulates the insulin/IGF-1 signaling pathway, where reduced signaling extends lifespan by 18-32% in animal models, according to the American Physiological Society 1
Physical activity impacts mTOR pathway activity, which when appropriately regulated doubles lifespan in C. elegans and extends lifespan by 20% in mice, as reported by the National Academy of Sciences 1
Physical activity prevents frailty accumulation, which correlates with disability, falls, delirium, and mortality, as stated by the American Geriatrics Society 1

The American Cancer Society guidelines identify that for non-smokers, weight control, dietary choices, and physical activity are the most important modifiable determinants of cancer risk, they explicitly group these together rather than isolating one factor, as per the American Cancer Society 2, 3
At least 150 minutes per week of moderate-intensity activity is sufficient to reduce all-cause mortality, as recommended by the World Health Organization 1

The hierarchy of modifiable determinants of lifespan operates with physical inactivity as the primary cause, followed by obesity/weight control, dietary patterns, and tobacco use, as outlined by the American College of Cardiology 1, 2, 3