Effect of napping on a bean bag chair on sleep stage, muscle activity, and heart rate variability

Background: Although ample evidence has demonstrated that daytime napping is beneficial for health and cognitive performance, bedding for napping has not yet been scientifically investigated. Objectives: To explore the effect of a bean bag chair on daytime napping and physiological parameters related to sleep. Methods: Fourteen healthy participants were enrolled within the context of a randomized, single-blind, crossover study to evaluate the effects of a bean bag chair in comparison with those of a urethane chair manufactured to have a similar shape. Electroencephalogram, electromyogram, and heart rate variability were recorded and compared between wakefulness and napping. Results: Electroencephalogram analyses revealed no significant differences in sleep architecture or frequency components; however, a significant decrease was found in electromyogram recordings in the trapezius muscle, which represents the neck region (p = 0.019). Additionally, a significant main effect of bedding in the low-frequency/ high-frequency ratio (F[1,20] = 4.314, p = 0.037) was revealed. Conclusions: These results suggest that napping in a bean bag chair may provide a comfortable napping environment involving muscle relaxation and proper regulation of the autonomic nervous function.