One in every three adults in the US doesn't get enough sleep on a regular basis, according to the Centers for Disease Control and Prevention. I've been interested in the issue of sleep for a while, ever since I realized the powerful negative effect that a consistent lack of sleep has on my personal productivity. When sleep-deprived—a state that can be created cumulatively from getting short-shrifted as little as 20 minutes per night for several nights in a row—most people experience a decrease in focus, in reaction time, and even in some unusual skills, such as creativity and problem-solving.
Many of us need to sleep more, but how do we do it?
What Is Your Sleep Need?
One of the best sleep resources I've read is a book by Till Roenneberg called Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired. It's a nerdy book filled with scientific detail, but also highly readable. Roenneberg calls himself a "clock researcher," and the clock he studies is the internal human clock, the one that makes us sleep or prevents us from falling asleep.
Internal Time goes to great lengths to explain why people have different sleep needs. The whole business of being an early bird (now often called a "lark") or a night owl is real, and it seems to be genetic. Our sleep needs are largely shaped by genes, but they're also influenced to some degree by other cues in the world, some of them social and some of the celestial, like sunlight.
To simplify just a few points Roenneberg makes, people aren't just larks or owls. They are also short sleepers or long sleepers. Saying adults need on average somewhere around seven hours of sleep per night is exactly that, an average. Some rare people function just fine on five hours per night. They may even struggle to sleep more than that. Other equally rare individuals need eleven hours of sleep to feel rested.
The way to determine whether you're a lark, owl, short sleeper, long sleeper, or something in between is to track your sleep on free days. Sleep on free days simply means a sleep session when you can choose what time you want to go to bed and you can sleep as late as you want. Typical 9-5, M-F knowledge workers would track their free day sleeps Friday to Saturday and Saturday to Sunday, provided there are no obligations in the morning.
How to Track Your Sleep
Tracking your sleep on free days takes little more than a notepad and the ability to remember to write down when you went to bed and when you woke up. I think it's easier to do it with some kind of technology to help you track, so you don't have to remember.
Most of the best activity trackers include automatic sleep-tracking. The Misfit Ray is one of my favorites to wear to bed because it's tiny and lightweight, and therefore comfortable and not distracting while I sleep. I also like that the companion app makes it easy to adjust the sleep and wake times in case the record is off. When I hang out on the couch for half an hour before bedtime, sometimes I'm so still that the Misfit Ray thinks I've already gone to bed.
Occasionally people tell me they've found wrist-worn devices to be unreliable for sleep-tracking. There are other options.
On the cheap and somewhat unreliable end are apps you can install that use your smartphone's motion sensor to detect movement while you sleep. You turn on the app and leave your phone on the mattress overnight. I can't recommend a specific one, but search any app store for "sleep tracker," and you'll find some options.
On the more expensive and more accurate end are mattress sensors and smart mattresses, such as the Sleep Number it bed. These products are generally fitted with heart rate sensors and sometimes respiration sensors, too, which allow for a deeper and more accurate analysis of your time in bed.
However you decide to track your sleep, hopefully you'll notice a pattern in your numbers. Larks, according to Roenneberg, usually have a sleep time and wake time on free days that's pretty close to their weekday times. Owls sleep much later on free days, and they often sleep longer to make up for cumulative sleep deprivation that they experience during the week.
A Trick for Night Owls
Night owls who have a strict start time on work days often have a hard time going to sleep early enough to get their required number of hours of sleep. The reason is their internal clock tells them that 10 p.m. is too early to be sleepy, even if that's the ideal bedtime for, say, a 6:30 a.m. alarm.
One of the best bits of advice I found in Internal Time is a way for night owls to trick their bodies into falling asleep earlier, and it's surprisingly simple. In Roenneberg's research (he has a huge corpus of data collected from surveys), he found that night owls who spent up to two extra hours in the outdoors during daylight were able to adjust their sleep to be as much as one hour earlier. Sunshine, it seems, helps owls feel sleepy earlier. In urban areas, where workers spend their days in offices and commute in cars or underground on subways, people don't spend much time without a roof over their heads. Spending a lunch break taking a walk or commuting by bicycle or by foot could increase sunlight exposure and therefore help owls get more sleep.
Other Sleep tech Tricks
With the latest updates to iOS, Apple has put some new features related to sleep in its alarm clock. If you haven't explored them yet, I highly recommend you do. They're in the Clock app.
Now, you can set an alarm to not only wake up, but also one that reminds you before bedtime so you don't stay up too late. New alarm tones in the Option link in the app are so much better than before, too. There are waking songs that gradually increase in volume and are softer on the ear than a blaring horn.
I mentioned that I like the Misfit Ray for sleep tracking, and its app has some great sleep-assistant features, too. Similar to the iOS Clock app, you can set a gentle alarm tone to wake you, but you can also turn on ambient noise on a timer to help you fall asleep. Options such as campfire, rain, and waves are great for people who like a little white noise while lying in bed.
Get Some Rest
Not getting enough sleep is a real and serious problem, not only for productivity reasons, but also because it affects issues related to health and happiness. Because people in the US will have a few extra days off for Christmas and New Year's Day, now is an ideal time to track your sleep and try to figure out how much you really need. Tinkering with your sleep habits until you find a few solutions that work for you could also be a worthwhile New Year's resolution.
For more ways to make the most of your time, see our roundup of The Best Productivity Apps and Services.