Exercise

Physical activity is one of the most consistently studied influences on lifespan. In a pooled analysis of 661,137 adults followed for a median of 14.2 years, people who did any leisure-time activity had a lower death rate than people who did none: 20% lower below the recommended minimum, 31% lower at the minimum and 39% lower at three to five times the minimum, after which the benefit levelled off [1]. The World Health Organization recommends 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous aerobic activity a week for adults, regular muscle-strengthening activity, and less time sitting [2]. The Exercise and longevity article summarises the main studies, the effect of exercise frequency and sitting time, the biological mechanisms and the limits of the evidence.

The section is divided into four subsections by type of activity. Cardio and aerobic fitness covers aerobic fitness and the training that raises it; fitness measured on a treadmill is one of the strongest single predictors of mortality (risk of death), with each 1-MET increase (a MET is the energy used sitting at rest) linked to 13% lower all-cause mortality (death from any cause) across 33 studies [3]. Strength and muscle covers resistance training, muscle mass, grip strength and age-related muscle loss; muscle-strengthening activity was linked to 10 to 17% lower mortality in a pooled analysis of 16 studies, with the largest reduction at about 30 to 60 minutes a week [4].

Balance, mobility and function covers balance training, flexibility, everyday physical function and fall prevention. Its main evidence comes from randomised trials (studies that assign participants to groups by chance) rather than studies of death rates: in 108 trials of adults aged 60 and over, exercise reduced the rate of falls by 23%, and balance and functional exercise by 24% [5]. Everyday movement covers walking and daily steps, sitting time, recreational sport, and yoga and tai chi. In 15 studies of 47,471 adults, those in the top quarter of daily steps had 53% lower mortality than those in the bottom quarter [6], and among more than one million adults, about 60 to 75 minutes of moderate activity a day offset the higher mortality linked to sitting more than 8 hours a day [7].

Most of this evidence is observational (it tracks people over time rather than assigning them to exercise), so the figures describe associations rather than proven effects of exercise, and some of the difference between active and inactive people reflects illness, income and other factors. Randomised trials confirm that exercise training lowers blood pressure and reduces falls [8, 5], but the largest trial with death as its main outcome found no overall mortality difference after five years in adults aged 70 to 77 [9].