Adolescents' preference for later school start times

School Attendance, Chronotype, and Day-of-the-Week Effect in Adolescent Male Basketball Players

Adolescents' conflict between circadian rhythm and early school start time is more pronounced in evening chronotypes, who tend to reduce sleep duration during school days compensating during the free days by oversleeping (i.e., social jetlag). Cumulative weekly sleep debt may impair sport performance, which relies on physical and cognitive skills modulated by sleep. We hypothesized that chronotype predicts sport performance, and that it may interact with the day of the week. Moreover, given the role sleep plays in motor memory consolidation, we tested the hypothesis that school attendance, and the related chronic sleep deprivation, might be detrimental for participants in a training phase. Ninety-three adolescent male basketball players performed multiple free throw sessions (n = 7880) during both the school and holiday periods. Chronotype and its interaction with the day of the week significantly predicted shooting accuracy when attending school, but not on holidays. Evening types' performance gradually decreased from Monday to Friday. Participants with a more unstable performance (i.e., who did not complete the acquisition of the free throw motor scheme) worsened their accuracy when attending school. Our results suggest that the impact of chronotype and day of the week on sport performance is related to the presence of an externally imposed sleep/wake schedule and is consistent with evening types' increased likelihood of experiencing social jetlag. Possibly due to early school start time, attending school worsened the performance of participants in a training phase. Further investigations are required to assess whether reducing the mismatch between biological and social clocks might improve sport performance, along with other aspects of adolescents' life.

Later school start time is associated with longer school day sleep duration and less social jetlag among Norwegian high school students: Results from a large-scale, cross-sectional study

The present study explored the associations between school start time and sleep habits among older adolescents, and whether these associations depended on circadian preference. The sample comprised 4010 high school students aged 16-17 years who completed a web-based survey on habitual school start time, sleep, and health. The survey included the Munich ChronoType Questionnaire, and the short version of the Horne-Östberg Morningness-Eveningness Questionnaire. Students were categorised according to habitual school start time (before 08:00 hours, 08:00 hours, 08:15 hours, 08:30 hours or after 08:30 hours) and circadian preference (morning, intermediate or evening). Data were analysed using two-way analyses of variance (school start time × circadian preference) and linear regression analyses. Results showed an overall effect of school start time on school day sleep duration (main effect, p < 0.001), with the latest school starters having the longest, and the earliest school starters having the shortest sleep duration (7:03 hr versus 6:16 hr; Tukey HSD p < 0.001). Similarly, later school starters generally reported shorter social jetlag and later school day wake-up times than earlier starting students (both main effect p < 0.001). Circadian preference did not modify these associations (interaction effects p > 0.05). In the crude regression analysis, 15 min later school start was associated with 7.2 min more sleep (p < 0.001). School start time remained a significant predictor of school day sleep duration when adjusted for sex, parental educational level and circadian preference (p < 0.001). Results suggest that school start time is a significant predictor of school day sleep duration among adolescents.

The Effect of Chronotype on Oppositional Behaviour and Psychomotor Agitation of School-Age Children: A Cross-Sectional Study

The aim of this study is to examine the relationship between chronotype, classroom behaviour and school performance in 140 healthy school-age children attending various levels of education during the 1st cycle during 2021 in Portugal. In this cross-sectional and quantitative study, the Chronotype Questionnaire for Children (to assess the chronotype) and the Conners Scale-a reduced version was presented to the teachers (to assess behaviours such as excessive movement, inattention and oppositional behaviours)-were used. The methodology of this study followed a comparative method since the independent variables were not controlled, and therefore, it was still possible to compare the differences between the morning and evening groups. Statistical methods were used such as multivariate analyses, inter-item correlations and reliability tests, and descriptive tests were used for the percentile analysis. The sample was divided into three groups based on the identification of the chronotype-morning, intermediate and evening types-to further study the relationship between these chronotypes, their academic performance and classroom behaviour were studied. A multivariate analysis of variance revealed that there was a higher rate of oppositional behaviour in the morning type and no differences in the school performance during the two semesters (covering all of the school periods) regarding the chronotype effect, even with the analysis of regression parameters and covariates. On the other hand, the morning-type children showed a greater amount of motor agitation and impulsivity after controlling for the gender covariate. Age had an effect on the chronotype, after controlling for the covariate parental education. This study highlights the need for further research on the chronotype of the morning children in order to regulate their behaviour. The data that were obtained raise questions that have not been yet considered in the literature in the area of education and infant development.

Sleep and Health-Related Characteristics among Adolescents during COVID-19: An Update

Two opposing effects on adolescents’ health during COVID-19 lockdown have been described: A beneficial one due to longer sleep times during school closures and a detrimental one of psychological distress. This study investigated how sleep and health changed in the course of the pandemic when schools were open again. Overall, 12,238 adolescents in Switzerland participated in three cross-sectional online surveys: In 2017 under regular conditions (control group), during pandemic school closures in 2020 (closure group), and in 2021 still under pandemic conditions, but schools were open again (postclosure group). Sleep behavior and health-related characteristics (health-related quality of life; caffeine, alcohol, and nicotine use) in all three groups and depressive symptoms in the closure and postclosure groups were assessed. The sleep period on school days was longer in the closure group (median 9.00 h, interquartile range 8.25–9.75) and similar in the postclosure (7.92, 7.00–8.50) compared to the control group (7.75, 7.08–8.33). Health-related characteristics were better during school closures and similar to worse in the postclosure compared to the control group. Depressive symptom levels were higher in the postclosure than in the closure group. Therefore, beneficial effects were specific to school closures and adolescents’ psychological distress increased over the course of the pandemic.

Association Between Homeschooling and Adolescent Sleep Duration and Health During COVID-19 Pandemic High School Closures

IMPORTANCE

Although negative associations of COVID-19 pandemic high school closures with adolescents' health have been demonstrated repeatedly, some research has reported a beneficial association of these closures with adolescents' sleep. The present study was, to our knowledge, the first to combine both perspectives.

OBJECTIVE

To investigate associations between adolescents' sleep and health-related characteristics during COVID-19 pandemic school closures in Switzerland.

DESIGN, SETTING, AND PARTICIPANTS

This survey study used cross-sectional online surveys circulated among the students of 21 public high schools in Zurich, Switzerland. The control sample completed the survey under regular, prepandemic conditions (May to July 2017) and the lockdown sample during school closures (May to June 2020). Survey respondents were included in the study if they provided their sex, age, and school.

EXPOSURES

High school closures during the first COVID-19 pandemic wave in Switzerland (March 13 to June 6, 2020).

MAIN OUTCOMES AND MEASURES

Sleep-wake patterns, health-related quality of life (HRQoL, assessed by the KIDSCREEN-10 questionnaire), substance use (caffeine, alcohol, and nicotine), and depressive symptoms (lockdown sample only; assessed using the withdrawn/depressed scale from the Youth Self Report). Multilevel regression models were used to assess sample differences and associations of health-related characteristics with sleep duration and depressive symptoms.

RESULTS

The total sample consisted of 8972 students, including 5308 (59.2%) in the control sample (3454 [65.1%] female) and 3664 (40.8%) in the lockdown sample (2429 [66.3%] female); the median age in both samples was 16 years (IQR, 15-17 years). During school closures, the sleep period on scheduled days was 75 minutes longer (semipartial R2 statistic [R2β*], 0.238; 95% CI, 0.222-0.254; P < .001) and the students had better HRQoL (R2β*, 0.007; 95% CI, 0.004-0.012; P < .001) and less consumption of caffeine (R2β*, 0.010; 95% CI, 0.006-0.015; P < .001) and alcohol (R2β*, 0.014; 95% CI, 0.008-0.022; P < .001). Longer sleep duration was associated with better HRQoL (R2β*, 0.027; 95% CI, 0.020-0.034; P < .001) and less caffeine consumption (R2β*, 0.013; 95% CI, 0.009-0.019; P < .001). In the lockdown sample, an inverse association was found between depressive symptoms and HRQoL (R2β*, 0.285; 95% CI, 0.260-.0311; P < .001) and a positive association was found with caffeine consumption (R2β*, 0.003; 95% CI, 0.000-0.008; P = .01).

CONCLUSIONS AND RELEVANCE

In this survey study, 2 opposing associations between school closures and adolescents' health were identified: a negative association with psychological distress and a beneficial association with increased sleep duration. These findings should be considered when evaluating and implementing school closures. Furthermore, the findings provide support for delaying school start times for adolescents.

Teachers' preference for later school start times

Early morning school start times conflict with biologically determined sleep phase preference and thus contribute to common sleep deficits. This conflict is most pronounced in adolescents, and numerous studies have confirmed that later school start times are beneficial for their sleep and health. However, the conflict continues to exist beyond adolescence and, accordingly, also teachers might benefit from later school start times, but this has gained little attention so far. Importantly, teachers’ resistance to delay school start time is one of the key barriers for a successful implementation and, therefore, teachers’ school start time preferences and influencing factors are important to consider. To this end, we conducted an online survey. Teachers (n = 694, 56.1% female) from 17 high schools in Zurich, Switzerland, participated in the study. They indicated their school start time preference. In addition, four predictor blocks were assessed: sociodemographic, school‐/work‐related, and sleep characteristics, as well as teachers’ perception of students in the first morning lesson. Mixed models were applied to predict the preference. The majority (51%) endorsed later school start times (median preferred delay 25.2 min). School start time, sleep characteristics and perception of students in the first morning lesson were significant predictors for the preference. Thus, teachers with more misaligned sleep and higher awareness for students’ issues in the early morning were more likely to report a preference. This suggests psychoeducation about sleep biology throughout life span to be an effective measure to increase teachers’ support to delay school start time, especially because also they themselves are likely to benefit from later school start times.