Napping Behaviors and Extracurricular Club Activities in Japanese High School Students: Associations with Daytime Sleep Problems

Abstract

Although engaging in evening naps and extracurricular activities are popular among Japanese high school students, the associations between these behaviors and daytime sleep problems were unclear. A questionnaire on daily life and sleeping habits was administered to 1314 high school students, aged between 15–17 years. The respondents were categorized by their after-school napping habits (did not nap, napped 1–2 days/week, napped ≥3 days/week), and their extracurricular activities (no activity, cultural club, athletic club). The mean nocturnal sleep duration on weekdays (± standard deviation (SD)) was 390 ± 56 min. This was significantly shorter in those students with a higher number of days/week spent napping (p < 0.001), and slightly longer for those in the athletic club (p < 0.001). Sleep problems—including subjective insufficient sleep, excessive sleepiness during class ≥3 days/week, and falling asleep during class ≥3 days/week—were reported by 64%, 55%, and 33% of respondents, respectively. A multiple logistic regression analysis showed significantly higher risks for excessive sleepiness among students taking naps ≥3 days/week, and who belonged to athletic clubs. In addition to those factors, students in cultural clubs revealed significantly higher risks for falling asleep during classes. Future studies are required to decrease daytime sleep problems associated with evening naps and extracurricular activities among high school students.

Determinants of Sleepiness among Pupils in Kanto District of Japan

“…In contrast to the present study, increased sleepiness was reported to be associated with fewer extracurricular activities in Canadian students [21]. However, consistent with the present study, students who belonged to athletic clubs and cultural clubs revealed significantly higher risks for falling asleep during classes [22]. Undesirably early morning arousal is reported to lead to impaired evening function with excessive sleepiness [23].…”

Sleep Habits in Pairs of Japanese High School Students and Their Mothers in Summer and Autumn

“…Regarding the behavioral aspects presented in Table 6 and Table 7 , watching TV seemed to have no adverse influence on sleep in the present participants. The use of electronic devices such as smartphones has been suggested to be associated with sleep problems in adolescents [ 35 , 36 ]. A notable finding was that the time spent using electronic devices by the high school students was remarkably higher on weekends compared to weekdays and that in the mothers.…”

“…The other point to be taught to high school students should be to avoid napping after returning home, which was answered by 25% of the students, who take a nap “several times a week” or “almost every day”. Although taking a short nap in the early afternoon, which is around the timing of the circadian dip, is known to have benefits such as preventing sleepiness and improving cognitive functions in the afternoon after the nap [ 37 ], napping after returning home in the late afternoon to evening has been reported to be associated with a later bedtime and daytime sleep impairments, such as excessive sleepiness [ 36 , 38 ]. The percentage in this study was relatively lower than that reported in the previous studies of Japanese adolescents [ 36 , 38 ].…”

“…These T-scores are based on a database of Japanese adults, and the higher the score, the better the sleep health [ 40 ]. The other items are not standardized; however, they were used to investigate the life and sleep habits in our previous study on Japanese high school students [ 36 ]. Questions on the time spent watching TV, studying, and using electronic devices, such as smartphones or electronic games, on weekdays and weekends were included in the questionnaire (questions 15 to 17).…”

“…For the other questions on the frequency of behaviors or sensations (questions 18, 19, and 22), the answer categories were partially different from those for question number 21. For the high school students, napping behavior after returning home was investigated (question 22) because this behavior has been reported to be associated with daytime sleep impairments, such as excessive sleepiness [ 36 , 38 ].…”