Physical Activity Intensity And All-cause Mortality: National Health Interview Survey Mortality Follow-up Study, 1990-2002

Abstract

PURPOSE: To examine the longitudinal association between physical activity intensity and all-cause mortality. METHODS: We followed 73,745 adult respondents to the 1990 and 1991 NHIS linking them to the National Death Index through December 31, 2002. Respondents reported the frequency, duration, and perceived intensity for 14 physical activity groupings done in the prior 2 weeks. We used age- and sex-estimated maximal oxygen consumption to ascribe physical activity intensity as moderate (< 60%) or vigorous ($≥ 60%). Using Cox proportional hazards analysis, we determined mortality hazard rate ratios (HRR) associated with weekly time spent in moderate- and vigorous intensity physical activity. Multivariate models controlled for age, sex, race, education, smoking, hypertension, BMI, weight loss, health status, days hospitalized, doctor visits, CVD, cancer, or activity limitation, and, as applicable, moderate or vigorous activity. RESULTS: We noted 9,846 deaths during a mean follow-up of 11.4 years. In multivariable-adjusted models, moderate-, and moderate plus vigorous intensity activity was inversely associated with all-cause mortality. We found no significant association for vigorous intensity activity alone. CONCLUSION: In this prospective cohort study of a nationally representative sample of U.S. adults, moderate-, and moderate plus vigorous intensity physical activity were beneficially associated with all-cause mortality. The lack of a significant association for vigorous intensity physical activity deserves further study. HRR and 95% confidence intervals (CI) for moderate- and vigorous intensity physical activity and all-cause mortalityTable: Caption not available