It’s not about how long you sleep, it’s about when you do.
A new study has found students who consistently sleep at the same time daily get better grades compared to peers with haywire sleep patterns, Nature reports.
Sleeping at irregular hours disrupts our circadian clock, which helps our body keep time for many biological functions, including sleeping. At night, the circadian clock usually tells our body to release melatonin overnight.
This means those who sleep at irregular hours like 3am, their melatonin is released later in the night, pushing back their circadian clock as well.
This causes the body to feel like it’s in another time zone, study author Dr Charles Czeisler said, as reported by USA College Today.
“That means if the student had an 8am class, it would actually be happening at 5am biological time,” Czeisler said.
For this research, the team studied 61 Harvard College students for 30 days using sleep diaries, and quantified sleep regularity using a novel metric, the sleep regularity index (SRI).
What they found reversed the common perception teens study better if they sleep longer. Those who sleep at irregular hours were found to get the same hours of sleep as those who sleep at regular hours anyway.
But it is how consistently they keep to the same sleep and wake cycle that matters the most for their performance in college – the more consistent their sleeping schedule is, the higher their Grade Point Average (GPA).
And the benefits of being a consistent night owl or early riser go beyond the classroom as well, such as our susceptibility to catching colds and gaining weight.
“When circadian rhythms are disrupted, it degrades many different physiological systems in the body and makes individuals much more vulnerable to adverse health outcomes,” Czeisler said.
While the researchers caution against drawing a definite link between irregular sleep pattern and bad grades, students should not totally disregard their findings as well.
Kristen Knutson, an associate professor of sleep medicine at Northwestern University and expert in sleep patterns and their relation to health, told CNN:
“It’s possible students with bad sleep habits also have other bad habits that are the reasons behind their poor grades.”
“That being said, if it is possible irregular sleep could impair a student’s ability to do well in school, we really need to understand this further.”
The key is to find a suitable sleep and wake cycle and then stick to it. You can choose to sleep at 9pm or 2am, as long as you sleep at the same time every day.
“It’s so simple to address, that’s why I call it a secret weapon,” Czeisler said. “Regular sleep and adequate sleep is the best secret to student success.”