Abstract

A growing attention has been paid to a rest (non-work) period to upgrade our working life. This is quite meaningful for overworking countries such as Japan, where several regulatory actions have been made towards duration of working hours. The most essential strategy for managing rest after work is to set its minimum duration as in the European Union’s Working Time Directive, i.e., consecutive 11 hours per 24 hour period (Minimum11). A series of research in our group provide evidence on the role of daily rest period (DRP) in health and well-being. The cross-sectional findings indicated decreases in stress responses and nonrestorative sleep in employees with DRP longer than 12 hours (Tsuchiya, et al, Ind Health. 2017). Diastolic blood pressure was found to be lower when DRP became 14 hours or longer (Ikeda, et al, J Occup Environ Med. 2017). Detailed analysis for sleep duration and quality revealed favourable results in a DRP-dose dependent manner (Ikeda, et al, in submission). Specifically, 6 hours of sleep needed at least 11 hours of DRP. Good quality of sleep as assessed the Pittsburgh Sleep Quality Index was possible by taking a sleep for 14 hours or more. The prospective data showed a decline in short (<6 hours) sleep among employees whose monthly frequency of Minimum11 decreased 1 year later if their commute time to work was less than 1 hour (Takahashi, et al, in preparation). Also, employees who persistently exposed to the monthly Minimum11 reported higher levels of short sleep and nonrestorative sleep when their commute time was longer than 1 hour. These associations were consistent after controlling for age, gender, weekly work hours, and psychosocial work characteristics at baseline. The secured DRP is thus expected to produce the benefit for us through optimised sleep and recovery.