We’ve been fascinated by the topic of sleep recently, mainly because most of us agree that we either don’t get enough of it or can’t seem to do it. For the latter, you can try this editor-approved trick, and for the former, well, that’s a lifestyle decision that may or may not hinge on the fact that you decided to start Netflix series at 10 p.m. (again).
We interviewed a sleep researcher about how much sleep we should really get each night, to which she explained seven to eight is the magic range (you can read more about why here). But does this mean we can go to bed at 2 a.m. each night and wake up at 9 a.m. and feel just as awake as someone who went to bed at 11 p.m. and wakes up at 7 a.m.? Is there an “optimal time” that science has deemed the proper time to hit the hay? See below for the answer.
We did some digging and came to this conclusion: It depends on genetics—yes, genetics—but in general, the earlier the better. A study published recently in Springer’s Cognitive Therapy and Research Journal found that individuals who described themselves as “evening” people and went to bed later had more negative, intrusive thoughts and rumination than those who went to bed earlier and described themselves as “morning” people.
Another study found that Japanese workers who went to bed later showed more depressive symptoms than those who went to bed earlier, while a newer study found that an earlier bedtime may actually ward off mental illness.
But, it may have more to do with consistency rather than the actual hour you fall asleep. Harvard researchers found irregular sleep patterns were associated with poorer performance and productivity—not staying up late or sleeping in. In fact, according to the results, you can go to sleep and wake up at whatever time you like. The only catch is you have to keep a steady schedule.
The study looked at 61 undergraduates for 30 days using sleep diaries and found if the participants went to sleep each night and woke up at the same time, they were more productive. Never does it specify that these times had to be particularly early. Charles Czeisler, MD, chief of the Sleep and Circadian Disorders Division at Brigham and Women's Hospital, told CNN, "If you go to bed at 2 and get up at 9, that's fine. You just have to consistently do the same thing." Plus, it'll help you get more REM sleep as well.
The Professional Opinion
In terms of a specific sleep time, sleep expert Shawn Stevenson told Yahoo! that the optimal sleep schedule would be from 10 p.m. to 6 a.m. because of our body’s natural circadian rhythm and the fact that it mimics the sun’s rising and falling. Matt Walker, PhD, head of the Sleep and Neuroimaging Lab at the University of California, Berkeley, agrees, telling Time.com, “When it comes to bedtime, there’s a window of a several hours—roughly between 8 PM and 12 AM—during which your brain and body have the opportunity to get all the non-REM and REM shuteye they need to function optimally.”
Your own unique “perfect” bedtime within that window depends on genetics—some people are more naturally predisposed to be night owls, while others prefer to sleep earlier and wake up early. So if you don’t tend to get sleepy until 11 p.m., don’t force yourself to go to bed at 9 p.m. in the hopes you’ll wake up feeling more refreshed. Most likely, this will backfire and you’ll toss and turn and wake up feeling groggier than if you had just gone to bed when you naturally started feeling sleepy.
The Sleep Trick
If you’re trying to pinpoint the exact time, the easiest way is to go backward. Figure out what time you need to wake up in the morning and subtract seven to eight hours, adding about 15 minutes for your body to fall asleep. Do this for about 10 days and Michael Breus, PhD, a board-certified sleep specialist, tells Yahoo! that you should start naturally waking up a few minutes before your alarm sounds.
Nota JA, Coles ME. Duration and Timing of Sleep are Associated with Repetitive Negative Thinking. Cognitive Therapy and Research. 2014;39(2):253-261. doi:10.1007/s10608-014-9651-7
Blum ID, Zhu L, Moquin L, et al. A highly tunable dopaminergic oscillator generates ultradian rhythms of behavioral arousal. Elife. 2014;3 doi:10.7554/eLife.05105
Phillips AJK, Clerx WM, O’Brien CS, et al. Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing. Scientific Reports. 2017;7(1). doi:10.1038/s41598-017-03171-4