Short sleep and late bedtimes are detrimental to educational learning and knowledge transfer: An investigation of individual differences in susceptibility.

Good sleep hygiene practices, including consistent bedtimes and 7-9 h of sleep/night, are theorized to benefit educational learning. However, individuals differ in how much sleep they need, as well as in their chronotype preference. Therefore, some students may be more vulnerable to the cognitive effects of sleep loss, later bedtimes and nonpreferred times of learning than others. One prominent example is the debate regarding whether sleep loss and later bedtimes affect classroom learning more in female or male students. To inform this gender-and-sleep-loss debate, we developed a virtual college-level lecture to use in a controlled, laboratory setting. During Session 1, 78 undergraduate students were randomly assigned to take the lecture at 12:00 (noon condition) or 19:30 (evening condition). Then participants wore wristband actigraphy for 1 week to monitor average and intraindividual variability in sleep duration, bedtime and midpoint of sleep. During Session 2, participants completed a test at the same time of day as Session 1. The test included basic questions that were similar to trained concepts during the lecture (trained items) as well as integration questions that required application of learned concepts (knowledge-transfer items). Bayesian analyses supported the null hypothesis that time of learning did not affect test performance. Collapsed across time of testing, regression analyses showed that shorter sleep durations and later bedtimes explained 13% of the variance in test performance. Longer sleep durations and earlier bedtimes predicted better test performance primarily in females, younger students and morning-types. Interestingly, students with above-median fluid intelligence scores were resilient to short sleep and late bedtimes. Our findings indicate that both sleep and circadian factors should be addressed to optimize educational learning, particularly in the students who are most susceptible to sleep loss.

Physical activity and associated factors among students attending evening classes / Fatores associados à atividade física em adolescentes estudantes do período noturno

Abstract The aim of this study was to describe the physical activity level and associated factors among students attending evening classes in public and private schools in a region of the city of São Paulo. The sample was composed of 1,844 adolescents of both sexes aged 15-20 years. Three public and private schools in the city of São Paulo were visited. Daily physical activity level was assessed through International Physical Activity Questionnaire that classifies physical activity level. Physical activity level was divided into insufficiently active (when subject reported less than 300 minutes of moderate to vigorous physical activities per week) and physically active (when subject reported more than 300 minutes of moderate to vigorous physical activities per week). Information related to risk behavior such as smoking and alcohol consumption was collected. Data were analyzed using logistic regression with three levels of data input and p<.05 as significance. The prevalence of physically active adolescents was 36.1%. Most active subjects were: A) younger boys with low socioeconomic levels; B) adolescents from private schools; C) adolescents that do not smoke or drink alcoholic beverages; D) those who do not attend formal exercise program; E) those who go to school to perform physical activities on weekends. Adolescents attending evening classes tended to be insufficiently active. We believe that school structure, working hours, and distance from home and workplace to school and risk factor should explain these data. Intervention programs could significantly contribute to increase the physical activity level among adolescents.

Resumo O objetivo do estudo foi descrever os fatores associados à atividade física de adolescentes que frequentam aula no período noturno de escolas públicas e privadas em uma região da cidade de São Paulo. Foram selecionadas três escolas públicas e três escolas privadas que ofereciam as séries acadêmicas do ensino médio na zona norte da cidade de São Paulo. A amostra foi composta de 1.844 adolescentes com idades entre 15 e 20 anos. A atividade física foi avaliada pelo Questionário Internacional de Atividade Física. Os adolescentes classificados como ativos foram àqueles que cumpriram a recomendação de no mínimo 300 minutos semanais em atividades físicas. Coletaram-se informações sobre o uso de tabaco e ingestão de bebidas alcoólicas. Empregou-se a regressão logística (significância de p< 0,05). A prevalência geral de adolescentes que cumpriam a recomendação da atividade física (>300 minutos/semanais) foi de 36,1%, se associando às seguintes variáveis: A) rapazes mais jovens e com menor nível socioeconômico; B) adolescentes que estudavam em escolas privadas; C) não fazer uso de tabaco ou bebidas alcoólicas; D) não exercer atividades profissionais remuneradas e; E) frequentar a escola nos fins de semana para praticar atividades físicas. O nível de atividade física dos estudantes de escolas públicas e privadas parece sofrer influência do período que frequentam as aulas, sugerindo a implantação de mecanismos de incentivo que aumentem a participação em atividades físicas. A estrutura escolar e programas de intervenção poderiam contribuir para incrementar o nível de atividade física entre adolescentes.