Does it Matter When You Sleep? Your Sleep Questions Answered

When it comes to sleeping, you’ve probably heard the common advice: aim to get 6 to 8 hours of sleep every night, and the hours of sleep before midnight are more valuable to the body than those acquired between midnight and rising.

Getting adequate sleep—both in quality and quantity—is essential to feeling well, being mentally sharp, preventing certain illnesses and regulating mood. But does bedtime also play a role in the sleep puzzle? Can you stay up late and still get out of bed well-rested enough to function?

Turns out, your beauty sleep may be even more important than you thought it was. In recent findings published in Neurology, there is a strong connection between insomnia or poor sleeping habits and your chances of having a stroke (and your ability to recover from a stroke!).

How did researchers conclude this? After reviewing 29 different studies on sleep, it became clear that having at least 7 hours of sleep a night is crucial to our health because sleep offers important restorative functions for the brain. The only time when your mind can truly rest and recover is when you’re not awake, so without that time, your brain is literally on overdrive… all the time. That means it won’t be as equipped to fight for you when it needs to – like during a stroke – because it hasn’t taken enough breaks. 

So, skip the all nighters and the Netflix binge watching and hit the cool side of the pillow. It’s better for your health than knowing what happens in Game of Thrones. (In all seriousness though, if you feel as though you may suffer from a sleep disorder, reach out to your doctor who may be able to give you assistance in helping you get a more sound sleep.)

We’re sharing everything you need to know about sleep and how to catch the most beneficial Z’s.

Why sleep is important

“When we sleep, the body goes into recovery mode: restoring, revitalizing and preparing for the next day ahead,” says Noah Siegel, MD, Board Certified Sleep Medicine Physician at Massachusetts Eye and Ear, Harvard Medical School. “Sleep allows the brain to consolidate memories—everything from facts and figures to motor skills.” By skimping on sleep, we don’t give the brain a chance to put things together from the day. This, he explains, is why pulling an all-nighter when studying for an exam won’t help you: There’s no time to store those facts in any useful way.

The brain’s glymphatic system (think of it as the housekeeping team) uses sleep time to clean out waste products generated within the brain during the day. Sleepiness is what signals us to rest to give the system a chance to tidy things up and take out the trash. To get to the point where the brain can dispose of this accumulation, we need at least 40 minutes of sleep, which explains why you can (hopefully) rise from even a moderate-length nap feeling more mentally clear.

What is circadian rhythm?

Circadian rhythms are the sleep/wakefulness cycles by which the body operates. It’s like an internal 24-hour clock that governs when we “should” be awake and asleep and is primarily connected to our environment. Circadian rhythms are observable in humans, animals, plants and bacteria. While the signaling for each organism differs, they tend to be related to light and the timing of daytime and nighttime in their respective environments. Ideally, we want to be asleep when it’s dark and awake when it’s light.

“Our bodies have been set up to be awake during daylight and rest at dark,” says Bill Fish, Founder of Tuck. “It was less than 150 years ago that electricity was invented, so as a species, we would wake with the sunrise to hunt or tend to the field and then retire at night.” These external cues—light and dark—signal the body to be awake or asleep, and we easily fall into rhythms in response to these.

Why can’t you sleep?

There’s many reasons why you can’t sleep, but a really likely one is that you’re over-consuming caffeine, sugar or are overly stressed.

Finding yourself unable to sleep more than five hours a night? Think back to what you consumed during the day. If sugary drinks (i.e. energy drinks, soda or too many sugary caffeinated beverages) are on that list, they are probably the culprit.

A study conducted by the University of California revealed this week that there’s a certain link between sugary drinks and sleep deprivation. Hmmm.

They surveyed 18,000 adults, and while the authors aren’t clear yet if drinking sugar-sweetened beverages causes people to sleep less, or whether sleep deprivation makes people seek out more sugar and caffeine to stay awake – both could be true.

“We think there may be a positive feedback loop where sugary drinks and sleep loss reinforce one another, making it harder for people to eliminate their unhealthy sugar habit,” lead author Aric A. Prather, PhD, assistant professor of psychiatry at UCSF says. “This data suggests that improving people’s sleep could potentially help them break out of the cycle and cut down on their sugar intake, which we know to be linked to metabolic disease.”

Their findings? People who regularly slept five or fewer hours per night also drank 21 percent more caffeinated sugar-sweetened beverages (including both sodas and non-carbonated energy drinks) than those who slept seven to eight hours a night. People who slept six hours per night regularly consumed 11 percent more caffeinated sugar-sweetened beverages.

A new study conducted by researchers at Baylor University and published in the American Psychological Association’s Journal of Experimental Psychology, found that people who put together a to-do list at bedtime had an easier time falling asleep. Hmmm.

“It’s a matter of getting things out of your head,” Michael K. Scullin, PhD, lead author of the study and director of Baylor University’s Sleep Neuroscience and Cognition Laboratory and assistant professor of psychology and neuroscience, tells Yahoo Lifestyle. “It turns out that writing things down that you’re worried about helps to ‘offload’ them … almost like you’re mentally checking those items off your to-do list. If you just cycle through your list in your head, then that rumination impairs your ability to fall asleep.”

Makes sense to us. But, there’s one more major takeaway: “I’d recommend writing on paper rather than using your phone,” says Scullin. “The light emitted from our phone decreases melatonin production, makes us feel more alert, and makes it harder to fall asleep.”

Challenge accepted. 

How to reset your circadian rhythm

You can reset your circadian rhythm by using natural light. The body is programmed to produce melatonin as the sun sets and stop producing it when dawn breaks to wake us up. However, you can accomplish the same effect with artificial lighting, controlling your environment to mimic the sun’s schedule, thereby putting yourself on a similarly-timed but offset-from-nature rhythm.

How to practice good sleep hygiene

“Dosing schedules,” as Dr. Siegel explains, involve intentionally exposing oneself to light (e.g. a sun lamp) during the time one needs to be awake and avoiding blue light, screens and other light sources when one needs to be asleep, even if these don’t align with what’s going on outdoors. Blackout curtains and sleep masks are effective ways to make a bright sleep environment extra conducive to rest; UV visors and lights placed throughout your home will help achieve daytime-like conditions if you’re awake during non-daylight hours.

Bill also recommends creating a bedroom environment that is conducive to sleep. “I strongly suggest charging your devices in another room,” he advises, noting that you don’t need to be woken by notifications during rest. “Make the room as dark as you can while still being safe. Find an alarm clock that emits a low light and invest in blackout shades that can block streetlights or even the sun in the morning.”

How to sleep through the night

And if you have trouble staying asleep? Bill suggests a white noise machine.“For less than $30, a white noise machine can mask the sounds outside your sleeping space. Your body needs at least 90 minutes to complete the full range of the sleep cycles, so if you’re woken in the middle of the cycle, your body essentially has to start over.”

Having a comfortable, dark and quiet environment will help keep your sleep schedule on track and your rhythms in order. If you have trouble sleeping through the night, follow these tips:

  • Get blackout curtains or use an eye mask to block out all light
  • Stop drinking caffeine six hours before your bedtime
  • Reduce screen time an hour before bed
  • Drink soothing tea
  • Use magnesium or melatonin

Does it matter when you sleep?

With all of that said, does it matter if you go to bed at 10:00pm and wake before dawn, or can you get the same quality sleep if you hit the hay just before the sun comes up?

As Dr. Siegel puts it, “It matters less when you go to bed than how consistent your bedtime is. As long as you keep a regular schedule, you’re more likely to have good quality and good quantity sleep.” That said, it’s less complicated—and requires fewer gadgets—to start winding down your night as dusk settles and to rise with the sun in the morning.

“You get more deep stages of sleep in the earlier part of your sleep time,” says Dr. Siegel. “REM sleep tends to occur closer to waking time, but that has less to do with what time of day it is and more with how long you’ve been asleep.”

Because your sleep architecture—the depth of the sleep stages, lengths and number of cycles of sleep you experience in a night—can change for the worse if your schedule fluctuates too often, Dr. Siegel stresses that a regular, predictable sleep schedule is the best thing you can do when it comes to sleep hygiene. “An ideal sleep is 7 to 8 hours, consolidated into one block of time, optimally when it’s dark,” he explains. If you need to manufacture that dark to fit your life, go for it. The length of the sleep is more impactful on your wellbeing.

Is 6 hours of sleep enough?

No, 6 hours of sleep is not enough. Bill adds, “Bedtime needs vary from person to person. While it is possible for people to work the graveyard shift, we want to aim to be at rest for 7 to 9 hours prior to the sun coming up.”

The takeaway

Your body wants to sleep on a schedule, so maintaining a similar bedtime and a similar waking time throughout your week is important. Sleep in alignment with your body’s internal clock. If you’re just never tired at 11:00pm, you don’t have to force yourself to lay in bed and stare at the ceiling for hours. Go to bed when you’re tired with the goal of having that time be consistent—about an hour earlier or later at most—each night.

“Protect your sleep and form good habits,” Dr. Siegel says, emphasizing the importance of prioritizing good rest.

Amy Height is a holistic health coach, triathlete and yogi traveling North America full-time to discover the best in nutrition and fitness. She shares healthy living ideas and plant-based, gluten-free recipes at From the Ground Up Wellness. Follow the adventures and find some fit-foodie inspiration on Instagram, amyheight.