The science of sleep and how to get better rest, as explained by a neuroscientist
Without serious examination, sleep can seem like one of biology’s worst ideas.
Lying unconscious for long stretches of time seems risky at best—being out of commission means being unaware of potential threats (housefires, alien attacks, predators), but some form of sleep has been shown to be present in pretty much every animal ever studied.
Researchers have even encountered sleep-like states in roundworms.
But how and how long creatures sleep varies a lot. Koalas cuddle up in the forks of trees to catch their zzzs for 18- 22 hours daily, whereas in the wild, giraffes can get by on as little as half an hour of sleep standing up.
People, on the other hand, need between 6-8 hours of rest nightly.
That’s between ¼ and ⅓ of a person’s life, spent in bed. So why do we spend so much time sleeping? What does sleeping do for our bodies that makes it necessary for us to spend so much of our time sprawled out (or curled up under the covers) with our eyes shut?
What we know about sleep
Up until the mid-to-late 20th century, most people thought of sleep as a passive activity during which the body and the brain were resting and recovering for the day ahead.
But as it turns out, while we sleep, our brains are doing necessary things to keep us healthy and maintain our quality of life. Sleep keeps our brains in shape and able to process and learn new things, and remember them at a later date.
There’s still a lot we don’t know about sleep, but one thing that is for certain is that we can’t survive without it. Sleep serves the crucial function of clearing our brains of toxins. And current data shows that without sufficient sleep, health risks increase. Poor sleep can also compromise overall health as symptoms of existing conditions worsen and the likelihood of illness rises.
How does my body know when to sleep?
Sleep is an integral part of our bodies’ daily natural cycles of rest and activity, known as Circadian rhythms. Our circadian rhythms are determined by an internal biological clock that lives in a part of our brains called the hypothalamus.
This internal clock is activated by the light that enters our eyes even when our eyelids are shut.
That’s why it’s so crucial for us to control our exposure to bright light (particularly blue light from screens) late in the evening, closer to when we want to go to bed. More than any other type of light, the shorter wavelengths from blue light cause the body to slow down production of melatonin, a necessary hormone in the sleep-wake cycle.
Our bodies’ reactivity to light is also why people who live in parts of the world where there are fewer hours of sunlight in winter may have trouble waking up (because it’s dark outside most of their waking hours).
What are some things I can do to improve my sleep?
If you’ve been having trouble getting good rest (and let’s face it, most of us do sometimes), here are some tips to help you get the sleep you need.
1. Stick with a schedule
Throughout the week (weekends, too), try to go to bed and get up at the same time. Avoid lie-ins and naps that could make it harder to keep to your schedule.
2. Banish screens from the bedroom
It’s tempting to read on your phone or watch TV until you drift off in your bedroom, but ultimately, the blue light these screens produce has been proven to be disruptive to sleep.
Give your eyes (and your internal clock) at least 30 minutes to an hour before bed without exposure to this kind of light.
3. Make movement a part of your day
Getting some exercise in on a daily basis can make a big difference in how well you rest. However, you should avoid working out within 3 hours of your regularly scheduled bedtime.
The endorphins exercise produces in your body aren’t conducive to drifting off to dreamland.
4. Manage your thoughts
It’s frustrating, but there’s something about getting cosy in our beds that can bring repetitive thoughts and worries to the forefront of our minds, especially if we’ve been putting off dealing with them all day.
Journalling regularly before you go to bed is an excellent way to wipe the slate clean, or if you’re having ongoing issues with unhelpful thoughts, you might consider working your way through an interactive programme like Evermind’s Constructive worry.
5. Limit caffeine
Sure, a coffee or tea may help you feel more ‘awake’ after a poor night’s sleep, but it could also be the start of an unhappy cycle of overdoing caffeine to stay alert during the day and feeling jittery and wide-awake when you’re ready to sleep at night.
Not only do studies show caffeine can decrease your total sleep time, it’s linked to increased difficulties falling asleep. So you’d be well-advised to avoid it, especially in the hours leading up to your normal bedtime.
6. Avoid alcohol
When you’re not sleeping well, a drink to help you drift off at bedtime is tempting. But while alcohol may help healthy people get to sleep and sleep deeply for a while, it diminishes your body’s ability to respond to light cues and suppresses melatonin, a key facilitator of sleep.
Alcohol too close to bedtime may also have you waking up more throughout the night to use the facilities, too.
Do you have trouble sleeping? Have you tried any of the above techniques? Share your experience with us at firstname.lastname@example.org.