10 February 2012

7 Hours is Optimal Sleep For High School Students Before A Test

After analyzing data of close to 2,000 students, a new Brigham Young University study found that 16-18 year olds perform better academically when they have seven hours of sleep. The U.S. Federal guidelines prescribe nine hours.

“We’re not talking about sleep deprivation,” says study author Eric Eide. “The data simply says that seven hours is optimal at that age.”

The study breaks down the optimal sleeping time by age.

The new study by Eide and fellow BYU economics professor Mark Showalter is the first in a series of studies where they examine sleep and its impact on our health and education. Surprisingly, the current federal guidelines are based on studies where teens were simply told to keep sleeping until they felt satisfied.

Video: The Benefits of Sleep

“If you used that same approach for a guideline on how much people should eat, you would put them in a well-stocked pantry and just watch how much they ate until they felt satisfied,” Showalter said. “Somehow that doesn’t seem right.”

In the new study, the BYU researchers tried to connect sleep to a measure of performance or productivity. Analyzing data from a representative sample of 1,724 primary and secondary school students across the country, they found a strong relationship between the amount of sleep youths got and how they fared on standardized tests.

But more sleep isn’t always better. As they report in the Eastern Economics Journal, the right amount of sleep decreases with age:

  • The optimal for 10-year-olds is 9 – 9.5 hours
  • The optimal for 12-year-olds is 8 – 8.5 hours
  • The optimal for 16-year-olds is 7 hours

“We don’t look at it just from a ‘your kid might be sleeping too much’ perspective,” Eide said. “From the other end, if a kid is only getting 5.5 hours of sleep a night because he’s overscheduled, he would perform better if he got 90 minutes more each night.”

The size of the effect on test scores depends on a number of factors, but an 80-minute shift toward the optimum is comparable to the child’s parents completing about one more year of schooling.

“Most of our students at BYU, especially those that took early-morning seminary classes in high school, are going to realize that 9 hours of sleep isn’t what the top students do,” Showalter said.


Brigham Young University
Eastern Economics Journal
Stayin’ alive: That’s what friends are for
Study answers how much last year’s teacher affects this year’s test scores
Dream Sleep Relieves Stress from Emotional Pain
Sleep Apnea: A High Risk Factor in Silent Stroke and Small Brain Lesions
Study Reveals Long Term Child Development Problems Resulting From Physical Punishment
Understanding Consciousness: Types of Consciousness
New Developments in Treatment of Asthma, Allergies and Arthritis
The Science of Understanding Stress