Abstract
INTRODUCTION: Current physical activity guidelines recommend that adults participate weekly in at least 150 minutes of moderate-intensity equivalent aerobic physical activity to achieve substantial health benefits. We used a nationally representative sample of data of US adults to estimate the percentage of deaths attributable to levels of physical activity that were inadequate to meet the aerobic guideline. METHODS: Data from the 1990 to 1991 National Health Interview Survey for adults aged 25 years or older were linked with mortality data up until December 31, 2011, from the National Death Index (N = 67,762 persons and 18,796 deaths). Results from fully adjusted Cox proportional hazards models were used to estimate hazard ratios and population attributable fractions for inadequate levels of physical activity (ie, less than 150 minutes per week of moderate-intensity equivalent aerobic activity). RESULTS: Overall, 8.3% (95% confidence interval [CI], 6.4-10.2) of deaths were attributed to inadequate levels of physical activity. The percentage of deaths attributed to inadequate levels was not significant for adults aged 25 to 39 years (-0.2%; 95% CI, -8.8% to 7.7%) but was significant for adults aged 40 to 69 years (9.9%; 95% CI, 7.2%-12.6%) and adults aged 70 years or older (7.8%; 95% CI, 4.9%-10.7%). CONCLUSIONS: A significant portion of deaths was attributed to inadequate levels of physical activity. Increasing adults' physical activity levels to meet current guidelines is likely one way to reduce the risk of premature death in the United States.