Leisure-time Physical Activity Throughout Adulthood

Abstract

PURPOSE: Limited evidence documents the benefits of leisure-time physical activity (LTPA) throughout adulthood on mortality risk. This study modelled LTPA patterns from adolescence into middle-age and their associations with all-cause, CVD, and cancer mortality. METHODS: In 1994-96, 315,059 adults (58% males) aged 50-71 yrs enrolled in the NIH-AARP Diet and Health study retrospectively described their participation in LTPA (hours/week) for approximate ages 15, 25, 35 yrs, and 50 yrs. LTPA patterns over these age-periods were modelled using semi-parametric group-based mixture models and 10 LTPA patterns throughout adulthood were identified. Participants were followed for mortality through 2011. Associations between life-course LTPA patterns and mortality were modelled using Cox proportional hazard models [(Hazard Ratios (HR) and 95% CI)] adjusting for age, sex, race, education, smoking, body mass index, and diet. The least active LTPA pattern (0 hrs/wk throughout all age-periods) was used as the referent group. RESULTS: Over 13.6 yrs of follow-up. a total of 71,377 deaths from all-causes, 22,219 deaths from CVD, and 16,388 deaths from cancer occurred. Compared to those who were consistently inactive throughout adulthood, participants who maintained LTPA participation over time were at lower risk for all-cause, CVD, and cancer mortality. For example, maintaining 7+ hrs/wk resulted in risk reduction of 29% for all-cause [HR: 0.71 (0.68, 0.73)], 24% for CVD [HR: 0.66 (0.62, 0.70)], and 10% for cancer mortality [HR: 0.90 (0.83, 0.97)]. Adults who were inactive at ages 15-35 (~1hr/week) but increased LTPA over time also had consistent reductions in risk for all-cause [HR: 0.65 (0.62, 0.68)], CVD [HR: 0.57 (0.53, 0.61)], and cancer mortality [HR: 0.84 (0.77, 0.92)]. In contrast, adults who reduced LTPA in adulthood had the lowest mortality benefits for all- cause and CVD mortality, and no benefits for cancer mortality. CONCLUSIONS: Participants who maintained or increased LTPA by their ~50’s had the lowest risk for mortality, independent of previous LTPA. LTPA during midlife (i.e., ~50yrs) rather than LTPA early in adulthood (i.e., 15’s through 35’s) seems to be most important for both all- and cause-specific mortality.