Sedentary Time and Physical Activity Across Occupational Classifications

Purpose: To examine differences in activity patterns across employment and occupational classifications. Design: Cross-sectional. Setting: A 2005-2006 Coronary Artery Risk Development in Young Adults (CARDIA) study. Sample: Participants with valid accelerometry data (n = 2068). Measures: Uniaxial accelerometry data (ActiGraph 7164), accumulated during waking hours, were summarized as mean activity counts (counts/min) and time spent (min/d) in long-bout sedentary (>= 30 minutes, SED >= 30), short-bout sedentary (<30 minutes, SED<30), light physical activity (LPA), short-bout moderate-to-vigorous physical activity (<10 minutes, MVPA(<10)), and long-bout MVPA (>= 10 minutes, MVPA(>= 10)) using Freedson cut-points. Employment status was self-reported as full time, part time, unemployed, keeping house, or raising children. Self-reported job duties were categorized into 23 major groups using the 2010 Standard Occupational Classification. Analysis: Omnibus differences were analyzed using adjusted analysis of covariance and repeated after stratification by race (black/white) and sex (female/male). Results: SED >= 30, SED<30, LPA, and MVPA(<10) differed significantly by employment and occupational categories (P <= .05), while MVPA(>= 10) did not (P >= .50). SED >= 30, SED<30, and LPA differed by occupational classification in men, women, blacks, and whites (P < .05). Mean activity counts, MVPA(<10), and MVPA(>= 10) were significantly different across occupational classifications in whites (P <= .05), but not in blacks (P > .05). Significant differences in mean activity counts and MVPA(<10) across occupational classifications were found in males (P <= .001), but not in females (P > .05). Conclusion: Time within activity intensity categories differs across employment and occupational classifications and by race and sex.