Original article

Scand J Work Environ Health 2011;37(5):418-426    pdf


Weekend sleep intervention for workers with habitually short sleep periods

by Kubo T, Takahashi M, Sato T, Sasaki T, Oka T, Iwasaki K

Objectives This study was conducted to determine whether extended sleep time during the weekend improves alertness and performance during the subsequent week for workers who are habitually short on sleep time.

Methods Daytime employees in the manufacturing industry [38.3, standard deviation (SD) 8.1 years old, mean weekday sleep ≤6 hours] participated in a study that lasted 3 successive weeks. Participants were instructed to stay in bed for ≥8 hours between 22:00–09:00 hours on weekends during the first week as a sleep intervention condition and keep their habitual sleep–wake patterns as a habitual weekend sleep condition beginning the weekend of the second week through Thursday of the third week. Half the participants underwent the conditions in one order and the other half in the reverse. Sleep was monitored by an actigraph. A psychomotor vigilance task, subjective fatigue, and blood pressure were measured on Monday and Thursday during the afternoon each week.

Results Sleep duration on weekends was approximately 2 hours longer per day during the intervention. However, sleep duration during weekdays following the intervention returned to shorter periods. Significantly shorter reaction times and a smaller number of lapses on the psychomotor vigilance task were found on Mondays after the intervention than after the habitual weekend sleep. The opposite results, however, were observed on Thursdays.

Conclusions Sleep extension on weekends may be effective in improving alertness and performance during the first days in subsequent weeks among workers with short sleep times. These benefits might be maintained if sufficient sleep duration continues.

This article refers to the following texts of the Journal: 2006;32(4):318-327  2006;32(6):502-514  2008;34(3):213-223  2003;29(3):171-188