Starting high school classes at 8:30 or 9 a.m. has been shown to improve teenagers' ability to stay awake and alert in school. High and middle schools in India usually start at 8:00 in the morning. To assess the effects of delayed high-school start times on sleep and motor vehicle crashes, researchers from America used a pre-planned, 1-hour delay in school start times for 10,000 middle and high school students. The students were asked to fill sleep habit questionnaires. It was found that just 35 percent obtained at least 8 hours of sleep each weeknight when they were required to be in school by 7:30 or 8:00 a.m. However, when school start times were delayed by 1 hour, 50 percent of the students said they slept at least 8 hours each weeknight. Further, a reduction in motor vehicle crash rates among 17- and 18-year-old drivers was also noted, which could be attributed to increased sleep and the associated improved vigilance. The above findings are consistent with the understanding that adolescents are biologically programmed to stay up later and wake up later than middle-aged people.
Journal of Clinical Sleep Medicine
December 2008