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The periodicity of sleep duration – an infradian rhythm in spontaneous living

Authors Wong SN, Halaki M, Chow CM

Received 14 September 2012

Accepted for publication 1 November 2012

Published 18 January 2013 Volume 2013:5 Pages 1—6


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 3

Shi Ngar Wong, Mark Halaki, Chin Moi Chow

Discipline of Exercise and Sport Science, University of Sydney, Sydney, NSW, Australia

Abstract: The sleep–wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults under spontaneous living conditions. Actigraph-measured sleep data for 13 healthy young male adults were collected over 14 consecutive days and analyzed for habitual sleep duration. The total sleep time periodicity was modeled using the cosinor method for each individual across the 14 days. The findings confirm the existence of periodicity in habitual sleep duration as there were clear periodic patterns in the majority of the participants. Although exclusive to each individual, the observed oscillations may be a resultant response of homeostatic sleep need, circadian timing, and/or social and environmental influences. These findings instigate further indepth studies into the periodicity of sleep duration in healthy individuals to provide a better understanding of sleep need in short versus long sleepers, in predicting work performance, and reducing sleepiness-related accidents following shift work, and how this periodicity may impact sleep treatment outcome in clinical populations.

Keywords: sleep regulation, homeostasis, habitual sleep, spontaneous living, healthy males

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