THURSDAY, June 16 (HealthDay News) -- Students who are night owls have worse grades in high school and the beginning years of college, research has shown.
However, a new study suggests that, as they adopt more traditional sleeping schedules, a change occurs.
"Their grades actually evened out," said study author Jennifer Peszka, an associate professor of psychology at Hendrix College in Conway, Ark. By the end of the senior year of college, the grades of the night owls she had followed since high school improved and were not much different than those of the morning people.
Peszka is due to present this latest finding Wednesday at SLEEP 2011, the annual meeting of the Associated Professional Sleep Societies, in Minneapolis.
Peszka and her colleagues first evaluated 89 students upon high school graduation. Before they entered college, the students answered questions about their sleep habits and gave the researchers access to their academic records.
Of those 89 students, 34 completed the same questionnaire after their freshman year in college, and 43 of them finished it after their senior year in college.
From the first batch of questions, the researchers classified the students as morning larks, night owls or regular robins. Larks are most alert in the morning; night owls do their best at night.
Regular robins are alert at 8 to 9 a.m., but tired by 10 p.m. or so, Peszka said.
The night owls slept about 41 minutes a night less than the others, the investigators found. They had other bad sleep habits, such as drinking caffeinated drinks close to bedtime and not keeping their bedtime and wake time constant during the week.
At the end of the freshman year, the night owls' grade point average (GPA) was 2.84, just below a B average, the study authors reported.
The larks and regular robins had an average GPA of 3.18, Peszka noted.
"It's only a third of a letter grade," she said of the difference. "But a third of a letter grade could, particularly at that place on the scale of GPA, be critical to keeping a scholarship or staying on a sports scholarship or keeping your parents satisfied."
Peszka also computed how much the students' grades declined during their freshman year at college compared to their last year of high school. It's typical, she said, for all students to have some decline during that period, as they adjust to college life.
"The owls actually declined by almost an entire grade point, 0.98," she said. The larks and robins declined, too, but by less -- two-thirds of a letter grade.
Fast forward to senior year at college, when the night owls' sleep habits improved, perhaps from necessity, Peszka suggested, and the difference in GPA had narrowed to the point where it was not significant from a statistical point of view.
"At the end of their [college] senior year, the larks and robins averaged a 3.45 GPA, the owls 3.32," Peszka said.
While the study shows only correlation between poor sleep and grades, Peszka said it is probably wise to advise night owls and others to pay attention to sleep habits if they want to maintain good grades.
Night owls may have to be especially attentive to sleep, she said. "I tell my students, 'Some people can eat cookies every day and never get fat. Some people have to pay attention to the cookies they are eating.' It could be morning types don't have to pay as close attention to their sleep habits. Evening types might have to be more cautious."
In another study presented at the conference, researchers from Rutgers and other universities found that night owls' poor sleep habits were tied to lower GPAs among 99 U.S. Air Force Academy cadets.
The two studies are among the first to look at educational response to sleep time and habits during the college years, said Donna Arand, clinical director of the Sleep Disorders Center in Dayton, Ohio, and a research associate professor at Wright State University Boonshoft School of Medicine.
She agreed that night owl students, with effort, can become more like larks. One of the simplest ways: "Set up a regular wakeup time," Arand suggested, such as 8 a.m. or 9 a.m. Then, a person will begin to get sleepier earlier in the evening. "Probably it will take about one to two weeks to reset your circadian rhythm," she said.
Because these studies were presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
To learn more about sleep and test your sleep IQ, visit the U.S. National Institutes of Health.
SOURCES: Jennifer Peszka, Ph.D., associate professor, psychology, Hendrix College, Conway, Ark.; Donna Arand, Ph.D., clinical director, Kettering Sleep Disorders Center, and research associate professor, Wright State University Boonshoft School of Medicine, both in Dayton, Ohio; June 15, 2011, presentation, SLEEP 2011, Minneapolis
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