Sleep Regularity and Predictors of Sleep Efficiency and Sleep Duration in Elite Team Sport Athletes

Shona L Halson; Rich D Johnston; Laura Piromalli; Benita J Lalor; Stuart Cormack; Gregory D Roach; Charli Sargent

doi:10.1186/s40798-022-00470-7

Sleep Regularity and Predictors of Sleep Efficiency and Sleep Duration in Elite Team Sport Athletes

Sports Med Open. 2022 Jun 17;8(1):79. doi: 10.1186/s40798-022-00470-7.

Authors

Shona L Halson^{1

2}, Rich D Johnston^{3

4

5}, Laura Piromalli⁶, Benita J Lalor⁷, Stuart Cormack^{4

7}, Gregory D Roach⁸, Charli Sargent⁸

Affiliations

¹ School of Behavioural and Health Sciences, Australian Catholic University, McAuley at Banyo, Brisbane, Australia. shona.halson@acu.edu.au.
² Sports Performance, Recovery, Injury and New Technologies (SPRINT) Research Centre, Australian Catholic University, Brisbane, QLD, Australia. shona.halson@acu.edu.au.
³ School of Behavioural and Health Sciences, Australian Catholic University, McAuley at Banyo, Brisbane, Australia.
⁴ Sports Performance, Recovery, Injury and New Technologies (SPRINT) Research Centre, Australian Catholic University, Brisbane, QLD, Australia.
⁵ Carnegie Applied Rugby Research Centre, Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK.
⁶ Western Australia Institute of Sport, Mt Claremont, Australia.
⁷ School of Behavioural and Health Sciences, Australian Catholic University, Melbourne, Australia.
⁸ Appleton Institute for Behavioural Science, Central Queensland University, Wayville, Australia.

Abstract

Background: Many elite athletes have suboptimal sleep duration and efficiency, potentially due to factors that may impact sleep onset and offset times. Variability in sleep onset and offset may negatively influence sleep. The sleep regularity index (SRI) is a novel metric for sleep regularity, however there are no published descriptions of SRI in elite athletes. Further, contributors to sleep efficiency and duration in elite athletes using objective measures have not been explored.

Methods: Sleep was monitored over a minimum of seven consecutive days (7 to 43)-in 203 elite team sport athletes (age range = 19-36 years; female, n = 79; male, n = 124, total sleep nights = 1975) using activity monitoring and sleep diaries. The sleep regularity index (SRI) was calculated to reflect the night-to-night shifts in sleep by accounting for changes in sleep onset and sleep offset. Sleep characteristics were compared between regular and irregular sleepers and important contributors to sleep efficiency and total sleep time were assessed using multiple linear regression models.

Results: The median sleep regularity index and interquartile range were 85.1 (81.4 to 88.8). When compared to irregular sleepers, regular sleepers demonstrated (1) significantly greater sleep efficiency (p = 0.006; 0.31 medium effect size [ES]), (2) significantly less variability in total sleep time (- p ≤ 0.001; - 0.69, large ES) and sleep efficiency (- 0.34, small ES), (3) similar total sleep time and (4) significantly less variation in sleep onset (p ≤ 0.001; - 0.73, large ES) and offset (p ≤ 0.001; - 0.74, large ES) times. Sleep characteristics explained 73% and 22% of the variance in total sleep time and sleep efficiency, respectively. The most important contributor to total sleep time was a later sleep offset time, while the most important contributors to sleep efficiency were an earlier bedtime and less variable sleep onset times.

Conclusions: Bedtime and a consistent sleep onset time are important factors associated with sleep efficiency in athletes, while sleep offset is an important factor for total sleep time. Coaches and staff can assist their athletes by providing training schedules that allow for both regularity and sufficiency of time in bed where possible.

Keywords: Athlete; Sleep regularity index; Team sport; Variability.