A new study has confirmed what most college students (and their professors — and parents) already suspected: Students’ sleep schedules are linked to their performance in the classroom. After evaluating the sleep habits of 61 students from Harvard College, researchers found that students who didn’t go to sleep or wake up at similar times every day were more likely to have lower grades.
For 30 days, the Harvard students kept online diaries of their sleep schedules, allowing the researchers to separate them into two groups: regular sleepers, who went to bed and woke up at around the same time every day, and irregular sleepers, whose sleep habits varied from day to day.Among the starkest differences between the two groups of sleepers was a difference in grade point averages. The researchers calculated a student’s sleep regularity on an index from zero to 100, with irregular sleepers receiving lower scores and regular sleepers receiving higher ones. For every score increase of 10 on the regularity index, the student had an average increase of 0.10 in their GPA.
One surprising finding: the study indicates that the disparities in academic performances between the two groups had little to do with sleep duration — the students with irregular sleep patterns got just as much sleep as their counterparts by sleeping during the daytime.
The differences in GPA were attributed to irregular sleep patterns, which cause the sleeper to have a delayed release of the sleep hormone melatonin and alter the body’s circadian clock. “Our body contains a circadian clock, which helps to keep time for many biological functions,” Andrew Phillips, the lead author of the study and associate professor of medicine at Harvard Medical School, told CNN. “One of the key markers of the circadian clock is melatonin. Usually, at nighttime, our circadian clock sends a signal that tells us to release melatonin overnight.” When melatonin is released later in the night, the circadian clock is pushed back as well, causing the body to feel like it’s in another time zone, study author Dr. Charles Czeisler said.
“That means that if the student had an 8 a.m. class, it would actually be happening at 5 a.m. biological time,” he said. “It’s as if they were traveling from the East Coast time zone to the Pacific time zone.”
Regular sleep has other benefits. Some students say that their irregular sleep patterns have been a hindrance to their academic performance, especially when their sleep habits impact their mental health.
Grace Axelrod, a freshman at New Hampshire Technical Institute, says that her trouble sleeping has made it more likely for her to have panic attacks and affects her ability to pay attention in her classes.
“A predictable routine is so important for children and adults alike,” she told USA TODAY College. “Sleep patterns might be the most important element in that routine. I need to know what to expect from my days, but I don’t because I don’t know when I’ll have a depressive episode.”
Other students say they did not see a measurable difference in their grades due to their irregular sleep patterns and even prefer their more irregular habits over seven-hour school days in high school. Madhan said that regular naps work to supplement her sleep schedule, Vanessa Miller, a J.D. and Ph.D. student at Penn State, said that she noticed a change in her college experience when she shifted her sleeping habits, if not an improvement in her grades. For her first two years as an undergraduate at the University of Florida, Miller stayed up until 4 or 5 a.m. and woke up at 11 a.m. But then she decided to start taking 9 a.m. classes to force herself to wake up earlier and engage her professors and classmates.
“I was just as productive when I went to bed at 4 a.m. than I was when I went to bed at 11 p.m.,” Miller remembers. “I completed my homework, I did well on tests, and put substantial effort into my papers. However, I wasn’t as engaged or productive as a student … I missed out on a lot of the campus life because I was up and productive at an hour when most people are asleep or about to head to bed.”
Miller said that when she began going to bed and waking up earlier, she became more committed to her school work and started “finally embracing being a student and making that my full-time job. I was able to be fully present in lectures, I was able to engage with professors in office hours, and I was able to attend more campus activities,” Miller said. “I wasn’t alone in a library at 2 a.m.”
For students looking to make the transition from night owl to early bird, Miller suggests establishing a morning routine and giving yourself something to look forward to in the morning. “A good breakfast, a satisfying workout, a shower, a walk, a quiet drive, a morning podcast, whatever it is,” Miller says. “I used to wake up at 8 a.m. for college football games even though I would go to bed at 3 a.m. Why? Because I had something to look forward to.”
This article was first published on USATODAY COLLEGE.