Walking in Relation to Mortality in a Large Prospective Cohort of Older US Adults

Introduction: Engaging in > 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity weekly is recommended for optimal health. The relationship between walking, the most common activity especially for older adults, and total mortality is not well documented. Methods: Data from a large U.S. prospective cohort study including 62,178 men (mean age 70.7 years) and 77,077 women (mean age 68.9 years), among whom 24,688 men and 18,933 women died during 13 years of follow-up (1999-2012), were used to compute multivariable-adjusted hazard rate ratios and 95% CIs for walking as the sole form of activity or adjusted for other moderate- or vigorous-intensity physical activity in relation to total and cause-specific mortality (data analysis 2015-2016). Results: Inactivity compared with walking only at less than recommended levels was associated with higher all-cause mortality (hazard rate ratio=1.26, 95% CI=1.21, 1.31). Meeting one to two times the recommendations through walking only was associated with lower all-cause mortality (hazard rate ratio=0.80, 95% CI=0.78, 0.83). Associations with walking adjusted for other moderate- or vigorous-intensity physical activity were similar to walking only. Walking was most strongly associated with respiratory disease mortality followed by cardiovascular disease mortality and then cancer mortality. Conclusions: In older adults, walking below minimum recommended levels is associated with lower all-cause mortality compared with inactivity. Walking at or above physical activity recommendations is associated with even greater decreased risk. Walking is simple, free, and does not require any training, and thus is an ideal activity for most Americans, especially as they age. (C) 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.