Dr. Mary A. Carskadon and her colleagues conducted an experiment testing what would happen to sleep and circadian rhythms in a group of young people for whom the transition from junior high to high school required a change in school starting time from 8:25 am in junior high to 7:20 am in high school. For some background, the definition for circadian is, “being, having, characterized by, or occurring in approximately 24-hour periods or cycles (as of biological activity or function)”, according to Merriam-Webster’s medical dictionary. The experiment had 25 kids participate in the study at two time points, in the spring of 9th grade(still Junior High), and in the fall of 10th. The student maintained their usual schedules, wore small activity monitors, and kept account of their sleep schedules for two consecutive weeks. At the end, the participants were tested on 3 things. They were tested in melatonin secretion, then an overnight sleep study, and lastly, daytime testing.
The results that Dr. Carskadon and her colleagues found were the following:
On the average school morning, the students woke up earlier for high school in comparison, but only 25 minutes earlier, despite the 65 minute difference between starting times for both schools. They also found that all the kids, at both times, showed 10:40pm being their average time that their bodies would transition from full wakefulness to sleep, usually to the lightest of the non-REM sleep stages (REM stands for rapid eye movement) . The participants went from an average of 7 hours and 9 minutes of sleep, to 6 hours and 50 minutes, which may seem insignificant because it is only a 20 minute difference, but they were already suffering a lack of sleep. Keep in mind, the average teen needs 9.25 hours of sleep each night and 7 hours is the average amount of sleep teens are getting, not just in this particular study. None of the students tested even got 8.25 hours of sleep. Another result they got was that they tested all kids in the morning with a Multiple Sleep Latency Test (MSLT). The test can distinguish physical tiredness and true excessive daytime sleepiness and it mainly discovers how readily a person will fall asleep in a conductive setting. Nearly half of them showed a sleep pattern that is similar to the sleep disorder narcolepsy, which is moving immediately into REM sleep before non-REM sleep, a reverse order. None of the 12 students had narcolepsy, but they did have an off pattern between their circadian rhythms and their school day wake up times which makes sense because at 8:30 in the morning, they fell asleep within 3 minutes.
Therefore, if we start school at 8:00, and wake up at about 6:45, in order to get the 9.25 hours of sleep that every teen needs on average, every kid would need to go to bed at 9:30. With school ending at 3, commuting home. having about an average of 2-4 hours of homework, afterschool sports or activities, family expectations, and chores, it is very difficult to do all that, and still have enough time to eat, shower, and breathe, AND still get in bed by 9:15 to be asleep by 9:30.
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