Valdez P, Ramírez C, García A
Laboratory of Psychophysiology, School of Psychology, Universidad Autónoma de Nuevo León, Monterrey, N.L., México.
Chronobiol Int. 1996 Aug;13(3):191-8. doi: 10.3109/07420529609012652.
There is a well-known tendency to delay and prolong our sleep during weekends (Saturday and Sunday), with an advance and reduction of sleep during workdays (Monday to Friday). The objective of this work was to determine if the changes of sleep during weekends are produced by a partial sleep deprivation or a lack of entraining of circadian rhythms to an advanced phase, during workdays. The subjects were 52 undergraduate female students, mean age = 17.5 years, SD = 1.32. All students attended school following a regular schedule, from Monday to Friday. Two groups of students were studied: one attended school from 07:00 to 12:00 h (morning group, n = 30); the other attended school from 14:00 to 18:00 (afternoon group, n = 22). None of the students worked or was engaged in other activity with a fixed schedule. All kept a sleep-wake diary for 2 weeks, in which they recorded their bedtimes, wakeup times, and sleep-onset latencies. The morning group delayed 47.4 min [t(29) = 4.72, p < 0.0001] and prolonged their sleep 118.2 min [t(29) = 9.4, p < 0.0001] during weekends. Although the afternoon group had the opportunity to maintain a delayed phase and a long sleep time throughout the week, they delayed their bedtime by 24 min [t(21) = 2.99, p < 0.01] during weekends, without changing their sleep duration. The findings suggest that the prolonged sleep during weekends is due to reduction of sleep during workdays, whereas the delay of bedtime seems to be associated with a tendency of the human circadian system to maintain a delayed phase with respect to the solar daylight period.
众所周知，人们在周末（周六和周日）有延迟和延长睡眠时间的倾向，而在工作日（周一至周五）则会提前并减少睡眠时间。这项研究的目的是确定周末睡眠的变化是由部分睡眠剥夺引起的，还是由于工作日期间昼夜节律未能调整到提前阶段所致。研究对象为52名本科女学生，平均年龄 = 17.5岁，标准差 = 1.32。所有学生周一至周五都按常规时间表上课。研究了两组学生：一组从07:00至12:00上课（上午组，n = 30）；另一组从14:00至18:00上课（下午组，n = 22）。没有学生工作或参与其他有固定时间表的活动。所有人都记录了两周的睡眠-清醒日记，记录了他们的就寝时间、起床时间和入睡潜伏期。上午组在周末延迟了47.4分钟[t(29) = 4.72，p < 0.0001]，并延长了睡眠时间118.2分钟[t(29) = 9.4，p < 0.0001]。虽然下午组有机会在一周内保持延迟的阶段和较长的睡眠时间，但他们在周末将就寝时间延迟了24分钟[t(21) = 2.99，p < 0.01]，而睡眠时间没有改变。研究结果表明，周末延长的睡眠时间是由于工作日睡眠时间减少所致，而就寝时间的延迟似乎与人类昼夜节律系统相对于太阳日照周期保持延迟阶段的倾向有关。
