DOI:10.6129/CJP.202206_64(2).0006
Chinese Journal of Psychology 2022, Vol.64, No.2, 233-262

The Monday Blues? The Impacts of Catch-up Sleep Duration and Social Jet Lag on Insufficient Weekday Sleep with Different Weekend Sleep Strategies

Fan-Chi Hsiao(Department of Counseling and Industrial/Organizational Psychology, Ming Chuan University; Department of Psychology, National Cheng Chi University), Chien-Ming Yang(Department of Psychology, National Cheng Chi University)

Abstract

Weekend catch-up sleep (CUS) is a strategy commonly used to cope with insufficient sleep during weekdays. Previous studies focused more on the usefulness of CUS in compensating for the sleep loss on weekday nights, but might have overlooked its possible negative influence due to “social jet lag (SJL)” resulting from the changes in the sleep-wake schedule. Thus, this study aimed to fill this gap by exploring the effects of different weekend sleep patterns, with different degrees of CUS and SJL, on subsequent sleep and daytime functioning with an experimental design. The study included 69 young healthy adults as participants. They were randomly assigned to three groups: a “delayed weekend sleep schedule” group (G1: n = 20), a “delayed weekend sleep schedule + CUS” group (G2: n = 24), and a “delayed weekend rising schedule + CUS” group (G3: n = 25). All participants had to go through a two-week study period: a baseline week and an experimental week. During the baseline week, participants had to restrict their time in bed (TIB) to 7 hours each night; during the experimental week, they were required to follow a regular sleep schedule with a restricted TIB of 7 hours on weekday nights, and to follow one of three experimental sleep patterns on weekends. The weekend sleep pattern of G1 consists of no CUS and 2 hours of SJL; G2 was composed of 2 hours of CUS and 2 hours of SJL; G3 involved 2 hours of CUS and 1 hour of SJL. Upon awakening from the last nights of the baseline and experimental periods, each participant rated their subjective sleepiness on the Stanford Sleepiness Scale (SSS) and emotion on the Profile of Mood State (POMS), and then came to the laboratory to complete the Psychomotor Vigilance Task (PVT) and the Continuous Performance Test (CPT) on the following Monday morning. Those groups with CUS (G2 and G3) showed higher wake after sleep onset (WASO) on weekend nights in the experiment period than the baseline. G3, compared to the other two groups, showed a trend of decreased negative emotion after the experimental night. However, G1 and G2 showed increased negative emotion compared to their baseline. The findings suggest that CUS might not be a good coping strategy to compensate for insufficient sleep on weekdays. More CUS might lead to larger SJL, which was found to be related to elevated levels of negative mood. The possible compensatory effect of CUS might be cancelled out by the negative effect of SJL.

Keywords: Catch-Up Sleep, Insufficient sleep, Monday Blues, Social Jet Lag