BOSTON — Take note, college students: Going to bed at a reasonable and consistent time every night might do wonders for your GPA, a new study finds.
Researchers at Brigham and Women’s Hospital in Boston examined 61 full-time undergraduate students at Harvard over the course of a month, hoping to find the correlation between sleep regularity and academic performance among college students.
Using a proprietary metric called the sleep regularity index (SRI), along with data on academic performance, and sleep duration and distribution, the researchers were able to conduct an analysis.
“Our results indicate that going to sleep and waking up at approximately the same time is as important as the number of hours one sleeps,” says Dr. Andrew J. K. Phillips, the study’s lead author and biophysicist at the hospital’s Division of Sleep and Circadian Disorders, in a news release.
Despite sleeping about the same number of hours on average, college students who had irregular sleep patterns were found to have lower grades than those who conformed their sleep cycle to a more natural circadian rhythm.
The idea that staying up saves you time is bunk, argues Charles A. Czeisler, senior author on the paper and Director of the hospital’s Sleep Health Institute.
“We found that the body clock was shifted nearly three hours later in students with irregular schedules as compared to those who slept at more consistent times each night,” he explains. “For the students whose sleep and wake times were inconsistent, classes and exams that were scheduled for 9 a.m. were therefore occurring at 6 a.m. according to their body clock, at a time when performance is impaired. Ironically, they didn’t save any time because in the end they slept just as much as those on a more regular schedule.”
A big part of the researchers’ study involved measuring circadian rhythms and the onset of melatonin during one’s sleep cycle.
“Using a mathematical model of the circadian clock, we were able to demonstrate that the difference in circadian timing between students with the most irregular sleep patterns and students with regular sleep patterns was consistent with their different patterns of daily light exposure,” says Phillips.
Namely, “regular sleepers got significantly higher light levels during the daytime, and significantly lower light levels at night than irregular sleepers who slept more during daytime hours and less during nighttime hours,” he explains.
While circadian rhythms can change, it is not recommended to change one’s sleeping times frequently.
To improve one’s circadian rhythm, the researchers recommend maximizing exposure to daylight and limiting exposure to LED devices before bed.
The study’s findings were published in the journal Scientific Reports.