One of the unfortunate facts of the modern world is that few people feel like they get enough sleep. I know from experience that the hectic schedule of the work-a-day routine can eat into what little time remains for sleeping, and the stress and worries of day-to-day life can distract us and prevent a good night’s sleep. But what is a good night’s sleep, anyway? And more importantly, how much sleep do you really need?
The Importance of a Good Sleep
The benefits of sleep to human health cannot easily be exaggerated. It often seems like sleep is a burden limiting our productive hours, but it is just as important as food and water to our survival. Even a single night with limited sleep can dramatically decrease the following day’s productivity. But why?
Unlike hunger, which can be easily sated with a single meal, the mechanism behind sleep is very complicated and is responsible for many life processes science is just beginning to understand. For instance, during your waking hours, one chemical in your body’s energy-creating cycle, adenosine, builds up in your blood as your body uses the energy broken down from food. Sleep allows the reactions that return adenosine into its useful form to occur; a failure to get enough sleep causes adenosine to begin to build up in the body. The National Sleep Foundation explains that a build-up of adenosine, one component of the condition often called “sleep debt,” causes a slowed reaction time and “makes you more prone to dangerous mistakes when driving,” at least partially to blame for 1,500 traffic fatalities a year.
But the lack of sleep doesn’t just cause a dramatic loss of reaction time; instead, there are many other more subtle psychological effects of a lack of sleep, demonstrated in a number of sleep deprivation studies. Sleep helps the brain consolidate the day’s events into memories, and a lack of sleep can inhibit the proper formation of both long- and short-term memories. The PsyBlog details even more effects from one particular study, including reductions in the ability to plan, to hold attention, and even to resist bad habits. For a detailed look at the science of sleep, this TED talk by a circadian neuroscientist (a scientist that studies the day-night cycle’s effects on the brain) named Russell Foster provides some fascinating information.
Clearly, sleep is important, both for daily functionality but also long-term mental and physical health. But how can we tell how much sleep we really need?
The Magic Number
Obviously, different ages of people sleep for different amounts of time, as anyone who is the parent to a teenager can tell you! After many years of studies, sleep experts have settled on recommendations, sorted by age, for the ideal amount of sleep per night. From birth through the teenage years, the amount of sleep a healthy human requires drops precipitously, from fourteen to seventeen hours for a newborn, to eight to ten for teenagers. For adults, the healthy amount of sleep settles out at seven to nine hours per night.
However, there really is no single “magic number” for all adults. Experts are quick to point out that the amount of sleep a healthy adult may require is widely divergent from another similarly-situated adult, and that heredity, genetics, and lifestyle have a lot to do with where that number falls. Obviously, seven to nine hours is a large range, although recent scholarship has decreased that range. As reported in the Wall Street Journal, mortality rates appear to be higher for those adults who sleep more than 7.4 hours a night, while those who sleep between 6.5 to 7.4 were the healthiest in the long term. But, as the scientists involved in the study were quick to admit, correlation is not causation, and they haven’t yet pinpointed a mechanism that would necessarily cause mortality to rise when sleeping longer than a certain number of hours.
Therefore, it seems best to limit sleep to seven to eight hours a night for a healthy adult. But how can you manage to even make that goal when life can be so hectic?
One of the most important things for a good night’s sleep is to remove electronic distractions. Given my background, I know how hard it is to avoid technology, but it is vital to allow our bodies to get into the “mood” for sleep. One of the key mechanisms that causes our bodies to realize that it’s time for sleep is light; the circadian rhythm is largely governed by the day-night cycle of the Earth’s rotation. A fascinating article in Scientific American discusses a research study that demonstrated that a mere two hours of tablet use before bedtime suppressed the release of melatonin, the hormone most responsible for making you feel tired and ultimately delaying sleep. Avoiding screen time in the evenings, and reducing the glare from alarm clocks or other devices on the nightstand, will help to stimulate the release of melatonin and give you that comfortable drowsiness that leads to effective sleep.
Given that sleep is a rhythm, like many of the other cycles in the body, maintaining a rhythm is important. I know that it is tempting to sleep in on the weekends, but it is often better for long-term sleep health to maintain a similar schedule both weekday and weekend. This way, the body knows that a certain time of night is always bedtime, and thus begins to secrete the hormones necessary to begin the sleep process.
Finally, all parents know that young children need a very strict schedule for sleeping or chaos can occur. But adults are much the same in their need for a stable bedtime ritual; adults just don’t voice their discontent in quite the same way as toddlers! Try to establish a series of stable evening behaviors, avoiding the bright glare from screens, and start turning down the lights in advance of when you’ll actually settle down in bed. By setting up your schedule this way, you prepare your body for a restful sleep.
As we’ve seen, sleeping is a vital part of a daily routine, a lot more than many people realize. It doesn’t just feel great to wake up refreshed after a solid night’s sleep, but it is important for your productivity and your overall health. As an adult, seven to eight hours of sleep is ideal; let me know in the comments if you can think of any other sleeping tips that work for you!
– Robert J Hudson
Robert is a proud father of two cool boys, sleep researcher and a chief editor at SnoreNation.com where he talks about snoring, sleep disorders, sleep health, and science. You can follow him and get in touch on Google+.