学进去

   Julie boergers, Ph．D a sleep expert from the Bradley Hasbro Children's Research Center, recently led a study connecting later school start times to improved sleep and mood in teens．

"Sleep deprivation is common among teenagers, with potentially serious impacts on mental and physical health, safety and learning.Early high school start times contribute to this problem，"said Boergers."In this study, we looked at whether a delay in school start time would change students' sleep patterns, sleepiness, mood and caffeine(咖啡因)use."

Beorgers' team conducted the School Sleep Habits survey among boarding students attending an independent high school both before and after their school start time was experimentally delayed from 8 to 8:25 a.m.during the winter term.The delay in school start time led to a significant increase (29 minutes)in sleep duration on school nights, with the percentage of students receiving eight or more hours of sleep on a school night jumping from 18 to 44 percent The research found that younger students and those sleeping less at the start of the study were most likely to benefit from the timetable change.Daytime sleepiness, low mood and caffeine use were all significantly reduced after the delay in school start time.The later school start time had no effect on the number of hours students spent doing homework, playing sports or taking part in activities outside class. And once the earlier start time changed back during the spring term, teens reverted(恢复)back to their original levels.

Beorgers said that these findings are important for public policy."The result of this study add to a growing body of research showing important health benefits of later school start times for adolescents, " she said, " and we have students who are more alert(机敏的), happier, better prepared to learn, and aren't dependent on caffeine and energy drinks just to stay awake in class."