The Importance of a Good Night’s Sleep
It may seem obvious that sleep is beneficial. Even without fully grasping what sleep does for us, we know that going without sleep for too long makes us feel terrible, and that getting a good night's sleep can make us feel ready to take on the world.
Sleep makes us feel better, but its importance goes way beyond just boosting your mood or banishing under-eye circles.
Scientists have gone to great lengths to fully understand sleep's benefits. In studies of humans and other animals, they have discovered that sleep plays a critical role in immune function, metabolism, memory, learning, and other vital functions. Adequate sleep is now seen as a key part of a healthy lifestyle, and can benefit your heart, weight, mind, and more.
A study published in the British Medical Journal photographed and rated healthy adults after a restful eight hours of sleep and then again after no more than five hours of sleep—and the “eight hours of sleep” photos won hands-down. The study concluded that “sleep-deprived people are perceived as less attractive and less healthy compared with when they are well rested.”
Other beauty-related benefits of adequate sleep include its effects on hair and skin. Hair health and growth patterns can be altered by lack of sleep, resulting in worsened male pattern baldness in men and thinning hair in women. Why? A full night’s sleep allows the proteins in hair strands to replenish and rejuvenate, while lack of sleep doesn’t. Additionally, getting enough sleep improves the look of wrinkles, since moisture produced during the body’s natural rest cycle hydrates and plumps fine lines. Inadequate sleep, however, can accentuate wrinkles.
Looks aren’t all that suffers from sleep deprivation, though. Check out the National Sleep Foundation’s white paper on sleep. Lack of sleep adversely affects your immune system, cardiovascular system, blood sugar, brain function and weight. For example, when you don’t get enough sleep, you feel worn down—because you are.
Donna Arand, Ph.D., DABSM, clinical director of the Kettering Sleep Disorders Center in Dayton, Ohio, and contributor to the National Sleep Foundation’s white paper on sleep, says, “Not getting enough sleep makes you more vulnerable to picking up illnesses and not being able to fight them off. What’s going on is your immune system is degraded.” The less sleep you get, the weaker your immune system becomes. This leaves you open to viral and other infections, since infection-fighting cells are reduced when you’re sleep-deprived.
Likewise, lack of sleep can cause cardiovascular and blood sugar problems. “When you don’t get enough sleep, you have an inflammatory response in your cardiovascular system—in the blood vessels and arteries. We see the same thing in hypertension. If sleep deprivation continues long term, chronic inflammation has been linked to things like heart attack, stroke and diabetes. In one study, young, healthy adult males decreased their sleep time to about four hours per night for six nights. After six nights, every one of those healthy young men showed impaired glucose tolerance, a precursor to developing diabetes,” Arand notes.
Then there’s sleep deprivation’s effect on brain function. Arand points out, “We know that people who are sleep deprived have very poor judgment when evaluating their own performance. They think they’re doing well on memory or eye-hand coordination tests, but they’re not. The memory is slightly degraded when you’re sleep deprived and gets worse the more deprivation you have.” Other studies indicate that those who drive without enough sleep are as impaired as someone who’s drunk.
Don’t forget about the weight factor. There’s a link to sleep deprivation and obesity in adults and children. One study indicates that those who slept five hours per night were 73 percent more likely to become obese than those who slept seven to nine hours per night. This effect may be related to hormonal imbalances—since lack of sleep is linked to lower levels of the hormone leptin, which reduces hunger.
Hunger and Eating, Sleepiness and Sleep
While we may not often think about why we sleep, most of us acknowledge at some level that sleep makes us feel better. We feel more alert, more energetic, happier, and better able to function following a good night of sleep. However, the fact that sleep makes us feel better and that going without sleep makes us feel worse only begins to explain why sleep might be necessary.
One way to think about the function of sleep is to compare it to another of our life-sustaining activities: eating. Hunger is a protective mechanism that has evolved to ensure that we consume the nutrients our bodies require to grow, repair tissues, and function properly. And although it is relatively easy to grasp the role that eating serves— given that it involves physically consuming the substances our bodies need—eating and sleeping are not as different as they might seem.
Both eating and sleeping are regulated by powerful internal drives. Going without food produces the uncomfortable sensation of hunger, while going without sleep makes us feel overwhelmingly sleepy. And just as eating relieves hunger and ensures that we obtain the nutrients we need, sleeping relieves sleepiness and ensures that we obtain the sleep we need. Still, the question remains: Why do we need sleep at all? Is there a single primary function of sleep, or does sleep serve many functions?
The Learning Process and Sleep
Sleep, learning, and memory are complex phenomena that are not entirely understood. However, animal and human studies suggest that the quantity and quality of sleep have a profound impact on learning and memory. Research suggests that sleep helps learning and memory in two distinct ways. First, a sleep-deprived person cannot focus attention optimally and therefore cannot learn efficiently. Second, sleep itself has a role in the consolidation of memory, which is essential for learning new information.
Although the exact mechanisms are not known, learning and memory are often described in terms of three functions. Acquisition refers to the introduction of new information into the brain. Consolidation represents the processes by which a memory becomes stable. Recall refers to the ability to access the information (whether consciously or unconsciously) after it has been stored.
Each of these steps is necessary for proper memory function. Acquisition and recall occur only during wakefulness, but research suggests that memory consolidation takes place during sleep through the strengthening of the neural connections that form our memories. Although there is no consensus about how sleep makes this process possible, many researchers think that specific characteristics of brainwaves during different stages of sleep are associated with the formation of particular types of memory.
"Sleep used to be kind of ignored, like parking our car in a garage and picking it up in the morning," says David Rapoport, MD, director of the NYU Sleep Disorders Program. But not anymore.
So, how much sleep is enough?
“We are all different,” says report author Michael H. Bonnet, PhD, a professor of neurology at Wright State University School of Medicine and the director of sleep laboratory at the Dayton Department of Veterans Affairs Medical Center, Ohio. “You need enough sleep so you can awaken feeling refreshed without an alarm clock.” Some people need more sleep than others, he says. This need is based on genes, age, sex, and previous sleep amount, among other things.
For most adults, however, between 7 and 9 hours a night is optimal, depending on how much stress and activity you experience during the day.
Most teens need about 8½ to more than 9 hours of sleep each night. The right amount of sleep is essential for anyone who wants to do well on a test or play sports without tripping over their feet. Unfortunately, though, many teens don't get enough sleep. Recent studies show that adolescent sleep patterns actually differ from those of adults or kids. These studies show that during the teen years, the body's circadian rhythm (sort of like an internal biological clock) is temporarily reset, telling a person to fall asleep later and wake up later. This change in the circadian rhythm seems to be due to the fact that the brain hormone melatonin is produced later at night for teens than it is for kids and adults. This can make it harder for teens to fall asleep early. School age children, ages 5 to 10 years old, usually need 10 to 11 hours of sleep, while preschoolers, ages 3-5 years, should have at least 11 to 13 hours of sleep a night.
5 Keys To A Better Night’s Sleep
If you find that night after night you are tossing and turning, unable to get a restful sleep, it may be time to really look at how you are spending your days, and what habits may be contributing to poor sleep. “Certain habits you’re unaware of could be sabotaging your sleep,” says Kristen L. Knutson, PhD, assistant professor and sleep specialist at the University of Chicago’s Department of Medicine.
1. It’s a no-brainer that drinking coffee or tea right before bed won’t do you any sleep favors, but you also need to watch your afternoon drinks. Many teas and drinks have caffeine, so be sure to check the labels on your favorite midday drinks, and be cautious of any drinks that boast “energy-boosting benefits”. Then, be sure to stop sipping them by 2 p.m., so there’s time for their effects to wear off. Naturally, coffee drinks pack a real wallop, so stay away from them after lunch. Afternoon slumps can be avoided by eating a protein rich breakfast and lunch, and staying hydrated with plenty of filtered water or caffeine-free herbal teas throughout the afternoon and evening.
2. Getting at least 30 minutes a day of exercise has been proven to help improve the both the quality and quantity of sleep. When you exercise, you experience smoother transitions between the various cycles and phases of sleep throughout the night. When you add exercise to your day, it has been shown that many fall asleep faster, stay asleep more easily, and remain in the deepest “Stage 4” sleep for a longer period of time. Aerobic exercise allows more oxygen to enter the blood and is thus considered to be the best type of activity to combat sleeplessness. Also, exercise that makes vigorous use of the leg muscles can act like a tranquilizer, making sleep much easier to achieve.
3. A hot bath or shower can do wonders for a stressed body and mind, allowing you to shift gears from “go” mode to “rest” mode. The combination of heat (and buoyancy in the case of a bath) causes blood vessels to dilate, lowering the blood pressure and speeding the flow of oxygen and nutrients to the muscles. Sleep usually follows the cooling phase of the body's temperature cycle. In addition, keep the temperature in the bedroom no higher than 68 degrees to influence this cooling phase associated with deep sleep.
4. Getting in a little gentle, restorative yoga before bed can help put your mind at ease, steady your breath, and reduce muscle tension without revving up your heart. Here is a relaxing exercise from the Healthy Lifestyles Yoga Studio that you can do to help your body prepare for sleep: Lie on your back with the soles of your feet together and your knees bent and dropping toward the floor. Place your arms, palms up, by your sides, keeping your shoulders back and your chest open. Close your eyes and inhale through your nose while slowly counting to four, then exhale while counting back down to one. Continue for 10 minutes, or as long as it takes you to feel fully relaxed.
5. Make your bedroom an inviting place to completely relax. Have soft lighting, and perhaps even play soft, soothing music. Take time to read or journal before turning the lights out. Maintain the quiet and peaceful space by keeping your laptop, ipad, and phone in another room. This allows you to consciously give yourself a mental break from your busy day, and gives you permission to put it all aside and fall into a deep and restful sleep.