File(s) not publicly available
Flat-out napping: The quantity and quality of sleep obtained in a seat during the daytime increase as the angle of recline of the seat increases
journal contribution
posted on 2018-09-13, 00:00 authored by Gregory RoachGregory Roach, Raymond Matthews, Anjum NaweedAnjum Naweed, Thomas KontouThomas Kontou, Charli SargentCharli SargentSome shiftwokers in the long-haul transportation industries (i.e. road, rail, sea, air) have the opportunity to sleep in on-board rest facilities during duty periods. These rest facilities are typically fitted with a seat with a maximum back angle to the vertical of 20°, 40°, or 90°. The aim of this study was to examine the impact of “back angle” on the quantity and quality of sleep obtained in a seat during a daytime nap. Six healthy adults (3 females aged 27.0 years and 3 males aged 22.7 years) each participated in three conditions. For each condition, participants had a 4-h sleep opportunity in a bed (02:00–06:00 h) followed by a 4-h sleep opportunity in a seat (13:00–17:00 h). The only difference between conditions was in the back angle of the seat to the vertical during the seat-based sleep periods: 20° (upright), 40° (reclined), and 90° (flat). Polysomnographic data were collected during all sleep episodes. For the seat-based sleep episodes, there was a significant effect of back angle on three of four measures of sleep quantity, i.e. total sleep time, slow-wave sleep, and rapid eye movement (REM) sleep, and three of four measures of sleep quality, i.e. latency to REM sleep, arousals, and stage shifts. In general, the quantity and quality of sleep obtained in the reclined and flat seats were better than those obtained in the upright seat. In particular, compared to the flat seat, the reclined seat resulted in similar amounts of total sleep and slow-wave sleep, but 37% less REM sleep; and the upright seat resulted in 29% less total sleep, 30% less slow-wave sleep, and 79% less REM sleep. There are two main mechanisms that may explain the results. First, it is difficult to maintain the head in a comfortable position for sleep when sitting upright, and this is likely exacerbated during REM sleep, when muscle tone is very low. Second, an upright posture increases sympathetic activity and decreases parasympathetic activity, resulting in a heightened level of physiological arousal. © 2018, © 2018 Taylor & Francis Group, LLC.
Funding
Category 1 - Australian Competitive Grants (this includes ARC, NHMRC)
History
Volume
35Issue
6Start Page
872End Page
883Number of Pages
12eISSN
1525-6073ISSN
0742-0528Publisher
Taylor & Francis, UKPublisher DOI
Peer Reviewed
- Yes
Open Access
- No
Acceptance Date
2018-04-16Author Research Institute
- Appleton Institute
Era Eligible
- Yes
Journal
Chronobiology InternationalUsage metrics
Categories
Keywords
Licence
Exports
RefWorksRefWorks
BibTeXBibTeX
Ref. managerRef. manager
EndnoteEndnote
DataCiteDataCite
NLMNLM
DCDC