Dr. Anne Marie Morse gets out of bed every day between 4 a.m. and 5 a.m., exercises, and then goes to work. As the Director of Child Neurology and Pediatric Sleep Medicine at Janet Weis Children’s Hospital in Danville, Pennsylvania, she has decided to wake up early to avoid traffic in her morning commute and prioritize self-care so she can better serve others.
Like Dr. Morse, many of us seek to balance our biological needs and daily tasks when deciding our sleep schedule. Some might find it difficult, but specialists say it’s worth the work. A new study published in the journal “Psychiatry Research” investigated how matching biological preferences to actual behaviors impacts mental health. Researchers were surprised to find that this match is not always the best option.
Sleep and morning rituals are personal and involve deliberate decisions. For Dr. Morse, finding the right balance means heading to work shortly after 6 a.m. Jeff Bezos schedules his first work meetings at 10 a.m.
“If you’re going to follow lessons learned from individuals who have proven a successful track record, listen to those who are not advocating for the extinguishment of sleep or that sleep doesn’t matter,” said Dr. Morse, who is also the spokesperson for the American Academy of Sleep Medicine. “Sleep is a keystone.”
Habit vs. preference
In 2017, scientists Jeffrey C. Hall and Michael Rosbash won the Nobel Prize in Physiology or Medicine for their findings on how the biological clock controls circadian rhythms in multicellular organisms, including humans. In lay terms, that means the biological clock regulates many of our genes, adapting our physiology to the different moments of the day. Sleep is one of those moments.
When we have a well-aligned circadian system, our biological clock tells us when to wake up, as many of us often experience. According to Dr. Jamie Zeitzer, co-director of the Center for Sleep and Circadian Sciences at Stanford University and one of the authors of the recent study on sleeping time, that happens because our brains predict that we will wake up at that time and start preparing for that. That’s what specialists call chronobiological preference.
But this preference is not absolute.
When conducting the study on the interconnection between sleeping time and mental health, Dr. Zeiter and other researchers found that, even though compatibility between our habits and chronobiological preferences is important, there is a moment when putting preference over habit can be harmful.
They surveyed 73,888 middle-aged and older adults in the United Kingdom and noticed that those who went to bed before 1 a.m. were less likely to develop conditions like depression and Generalized Anxiety Disorder than those who went to bed after that time.
Even for night owls, 1 a.m. sounds like a reasonable target. But how can we find a specific time that works for us?
Time vs. duration
Sleep discipline and virtue have long been connected in society, and our current obsession with productivity and competitiveness puts extra weight on our decisions about when to go to bed and the length of our sleep. Dr. Morse explained that we often make choices based on formulas that, despite working for other people, create a sense of constant failure and prevent us from performing at our best.
“One of the hazards when we start to put blanket statements, ‘everyone should do this one thing’ is that people who don’t thrive with this one thing start to adopt a mentality of ‘I just must not be good enough, strong enough, fast enough,’” she said.
That is why it’s important to learn our chronobiological preferences for the timing and duration of sleep.
Regarding timing, besides identifying our preference and keeping in mind the “before 1 a.m.” cutoff, we should also pay attention to the regularity of our sleep schedule to help our brain predict when we will wake up, which can benefit our cardiovascular health, immunity, athletic performance, mental health and metabolic system, Dr. Zeitzer said.
According to another recent study, published earlier this year by Oxford University Press on behalf of the Sleep Research Society, sleep regularity can be a stronger mortality predictor when compared to an optimal sleep duration under erratic schedules. After surveying 60.977 participants in the U.K., researchers were able to associate a higher sleep regularity with a 20%–48% lower risk of all-cause mortality, a 16%–39% lower risk of cancer mortality and a 22%–57% lower risk of cardiometabolic mortality.
For those who struggle to have a regular sleep schedule due to circumstances, the good news is that, like with any other habit, we can improve through practice. According to Oshin Vartanian, a professor of psychology at the University of Toronto, it might take a while to develop the habit, but it eventually can become second nature. “One of the really well-established phenomena in psychology is that when we’re trying to adapt or learn a new behavior, it’s very deliberate at the outset,” he said. “We have to break it down into steps, execute, learn what to do, and eventually, over time, things become automatized.”
Also, sleep regularity doesn’t mean waking up at the same time every day. Dr. Zeitzer and other specialists allow a window of 30 minutes to an hour, so don’t be discouraged.
Still, valuing regularity at rise time doesn’t mean we should neglect the sleep duration and go to bed at any time.
According to Dr. Zeitzer, sleep-deprived people experience decreased performance even if they don’t feel tired. “You can ignore it psychologically but not physiologically.” Our bodies cannot “get used” to sleeping fewer hours than needed. But how can we find the right sleep duration?
Dr. Zeitzer suggests we pay attention to how much we sleep on weekends and compare it to our sleep habits during the week. If we find a big gap, we’re probably sleep-deprived.
And if our schedule doesn’t allow us to sleep as much as our bodies would like to, we can make reality as close to our preference as possible. Even if we don’t get an optimal sleep duration, we can still get “pretty good” sleep, Dr. Zeitzer said.
The answer is in the waking hours
For Dr. Morse, the most important question we must ask ourselves when deciding our sleeping habits is: What do I want to accomplish in my day? “Sometimes we end up, by default, just accepting things pulling us in directions that really are malaligned with how we function best,” she said. “It is a matter of putting barriers and saying, ‘No, we’re going to do it at this time and not at this time.’”
This agency should apply both to the timing and duration of sleep. For Dr. Zeitzer, if we decide to sleep six hours a day instead of eight for reasons like exercising or spending time with family, that can be considered a healthy decision. “What you do with that extra time matters,” he said. For example, having less than ideal sleep to have a social life might be a good choice.
It sounds obvious, but it is precisely because our days will always have only 24 hours that making deliberate decisions about our sleep can be helpful.
“Ideally, you would have regular sleep, around eight hours every single night at the same time, exercise multiple times a week, eat healthy,” Dr. Zeitzer said. “And if you can do that, that’s great. For the vast majority of people who can’t do all that, what are you willing to give up? And what is the eventual cost of that?”
