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.