Physical activity recommendations and decreased risk of mortality

Background: Whether national physical activity recommendations are related to mortality benefit is incompletely understood. Methods: We prospectively examined physical activity guidelines in relation to mortality among 252 925 women and men aged 50 to 71 years in the National Institutes of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study. Physical activity was assessed using 2 self-administered baseline questionnaires. Results: During 1 265 347 person-years of follow-up, 7900 participants died. Compared with being inactive, achievement of activity levels that approximate the recommendations for moderate activity ( at least 30 minutes on most days of the week) or vigorous exercise ( at least 20 minutes 3 times per week) was associated with a 27% ( relative risk [RR], 0.73; 95% confidence interval [ CI], 0.68-0.78) and 32% ( RR, 0.68; 95% CI, 0.64-0.73) decreased mortality risk, respectively. Physical activity reflective of meeting both recommendations was related to substantially decreased mortality risk overall ( RR, 0.50; 95% CI, 0.46-0.54) and in subgroups, including smokers ( RR, 0.48; 95% CI, 0.44-0.53) and nonsmokers ( RR, 0.54; 95% CI, 0.45-0.64), normal weight ( RR, 0.45; 95% CI, 0.39-0.52) and overweight or obese individuals ( RR, 0.48; 95% CI, 0.44-0.54), and those with 2 h/d ( RR, 0.53; 95% CI, 0.44-0.63) and more than 2 h/d of television or video watching ( RR, 0.50; 95% CI, 0.45-0.55). Engaging in physical activity at less than recommended levels was also related to reduced mortality risk ( RR, 0.81; 95% CI, 0.76-0.86). Conclusions: Following physical activity guidelines is associated with lower risk of death. Mortality benefit may also be achieved by engaging in less than recommended activity levels.