Restricted and unrestricted sleep schedules of Asian adolescent, high-level student athletes: effects on sleep durations, marksmanship and cognitive performance

The impact of reduced sleep on school related outcomes for typically developing children aged 11–19: A systematic review

“…Jiang et al Five studies (Beebe et al, 2008(Beebe et al, , 2010Cohen-Zion et al, 2016;Jiang et al, 2011;Suppiah et al, 2016) had a quasi-experimental design. One study was based on a single case design (Beebe et al, 2009), although the study did not meet good standards for this type of design (Barlow et al, 2009;Horner et al, 2005).…”

“…Ten of the studies (Beebe et al, 2008(Beebe et al, , 2009(Beebe et al, , 2010Cohen-Zion et al, 2016;Huang et al, 2016;Jiang et al, 2011;Lo, Bennion, et al, 2016;Lo, Ong, et al, 2016;Suppiah et al, 2016;Voderholzer et al, 2011) used a sleep restriction protocol where the adolescents had the amount of sleep they were allowed dictated to them for four to seven nights at a time. With the exception of the study by Voderholzer et al (2011), these ten studies compared four to seven nights of restricted sleep with the same number of nights of unrestricted or extended sleep, typically ranging from 8-10.5 hours.…”

“…However, one study did not demonstrate that they had effectively reduced sleep. Suppiah et al (2016) aimed to have participants sleep for 7 hours 45 minutes for the five nights of the sleep restriction and sleep for a minimum of 9 hours for five nights in the unrestricted condition, yet the actual total sleep time of the two conditions did not meet this. Instead, the average total sleep time of the restricted sleep condition was 5 hours 42 minutes (with an average time in bed of 6.8 hours) and the average total sleep time of the unrestricted condition was 6 hours 8 minutes (average time in bed 8 hours).…”

“…All of the participants were typically developing adolescents, and most of them were representative of typical mainstream school populations. Four of the 17 studies stand out as having samples that are slightly less representative of the typical mainstream education adolescent population: three Singapore studies (Huang et al, 2016;Lo, Bennion, et al, 2016;Lo, Ong, et al, 2016) included only top high school students in their study and the fourth Singapore study, Suppiah et al (2016), focused on students of a high-performance youth development shooting academy. The findings of these studies are considered relevant to this review because the participants were typically developing adolescents who could have been in mainstream education if they were not in their more specialist settings and they were not in special or clinical populations.…”

“…Five of the studies in this review (Beebe et al, 2008(Beebe et al, , 2009(Beebe et al, , 2010Jiang et al, 2011;Suppiah et al, 2016) were underpowered to find an effect that exists because the sample size was too small. Three of these studies (Beebe et al, 2009;Jiang et al, 2011;Suppiah et al, 2016) found no effect, so we can conclude that there was not enough power to find an effect that may have been there rather than being able to clearly establish that there is no effect to be found (Altman & Bland, 1995). It is also surprising that the two other underpowered studies (Beebe et al, 2008(Beebe et al, , 2010 found an effect, given that they were underpowered.…”