Routine evening naps and night-time sleep patterns in junior high and high school students.

This study investigated the relationship between napping and night-time sleep patterns in junior high and high school students. A questionnaire concerning sleep-related lifestyle was given to about 10,000 junior high and high school students. Approximately 50% of the junior high and high school students take at least one nap per week. More than 30% of students take naps later than 17.00 hours. The late naps delayed students' bedtime; that is, onset of night-time sleep. The bedtime of students of university-bound high schools was later than that of students of vocation-bound high schools. The more frequently students took naps, the later they went to bed. Frequent late naps delayed bedtime and, hence, shortened the length of night-time sleep.