Impact of the state of emergency enacted due to the COVID-19 pandemic on the physical activity of the elderly in Japan.

[Purpose] In Japan, the government issued a state of emergency due to the spread of COVID-19 in April 2020. In this study, we measured physical activity before and after the state of emergency, and assessed the factors that affected physical activity. [Participants and Methods] We included thirteen elderly people living in Hiroshima Prefecture, Japan, in the study. The participants wore 3-axis accelerometer on their hips to measure physical activity for a week, before (in October 2019) and after the state of emergency. According to the median rate of decrease in physical activity (23.6%), we divided the participants into two groups: one group had participants with a high rate of decrease (low physical activity) and the other had participants with a low rate of decrease (high physical activity). [Results] The following factors decreased after the state of emergency: total physical activity, amount of moderate-intensity physical activity and activities of daily living, amount of light-intensity physical activity and walking, daily activity time, and daily steps. Statistical analysis showed that engaging in housework was associated with high physical activity. [Conclusion] Elderly people who engaged in household chores had a smaller decrease in physical activity. In order to reduce the decrease in physical activity and the risk of cardiovascular events, the elderly should perform as many daily activities and hobbies as they can while paying attention to the infection control measures.