Changes in accelerometer-measured physical activity and sedentary behavior from before to after COVID-19 outbreak in workers

Background: The COVID-19 pandemic may have reduced opportunities for engaging in physical activity (PA) and increased sedentary behavior (SB) among workers. However, most previous studies used self-reported assessments. This study aimed to examine the changes in accelerometer-measured PA and SB from before to after COVID-19 outbreak among Japanese workers. Methods: This one-year longitudinal study used data from the annual health check-ups of workers who lived in the Tokyo metropolitan area. Baseline and follow-up data were collected from June to November, 2019 and June to November, 2020, respectively. Participants were asked to wear the accelerometer on their hip during awake hours for at least 10 days in both the surveys. Before the analysis, considering the difference in wearing time, time spent in PA and SB were converted to the percentage of wearing time. To investigate the changes in PA or SB from before to during COVID-19 outbreak, paired t-tests were performed. Results: Of the 757 eligible participants, 536 were included in the analysis (70.8%). Participants' mean age was 53.3 years; 69.6% were female; and most were full-time employees. Time spent in PA decreased, regardless of weekdays or weekends, although changes on the weekends were not significant. Conversely, time spent in SB increased on both weekdays and weekends in 2020. These changes corresponded to approximately 10 minutes per day increase/decrease in PA/SB. Conclusion: Objectively measured PA decreased and SB increased by approximately 10 minutes per day after the COVID-19 outbreak among Japanese workers.