Patterns of objectively assessed sedentary time and physical activity among Japanese workers: a cross-sectional observational study

OBJECTIVES: To examine patterns of sedentary behaviour and physical activity, among Japanese workers with differing occupational activity types. DESIGN: A cross-sectional observational study in 2013-2015. SETTING: Two local communities in Japan. PARTICIPANTS: Full-time workers aged 40-64 years (n=345; 55% men) and who lived in two cities. MAIN OUTCOME MEASURES: From accelerometer data for 7 days, mean overall sedentary time, prolonged bouts of sedentary time and light-and moderate-to vigorous-intensity of physical activity (LPA and MVPA) as a proportion of accelerometer wear time and number of breaks per sedentary hour were identified for four time periods: working hours, workdays, non-work hours and non-workdays. These sedentary behaviour and physical activity measures in the four time periods were examined among workers with four self-attributed occupational activity types (mainly sitting, standing, walking, and physical labour), adjusting for sociodemographic attributes. Diurnal patterns of sedentary behaviour, LPA, and MVPA were examined. RESULTS: In working hours, those with a sitting job had significantly more total and prolonged sedentary time (total: p<0.001; prolonged: p<0.01) along with less LPA (p<0.001) and MVPA (p<0.001) and less frequent breaks (p