The Importance of Sleep
When you think of what makes up a healthy lifestyle, diet and exercise come to mind, but what about sufficient restful sleep? Some researchers consider the lack of sleep that many people experience is approaching epidemic levels.
According to scientific sleep studies, a lack of restful sleep causes a long list of issues:
- higher rates of obesity, high blood pressure, heart disease, stroke, Alzheimer's disease, some forms of cancer, and diabetes
- higher rates of depression and anxiety
- poor mood, energy, and motivation
- decreased focus, memory, and decision-making abilities
- decreased coordination, athletic performance, and higher rates of accidents
- lower levels of self-control, irritability, and more relationship problems
- inability to manage stress - small problems feel like much larger problems
- lowered immune function, frequent colds
- decreased sex drive
How Much Sleep Do We Need?
The National Sleep Foundation published a study by 18 sleep scientists and researchers in Sleep Health that shows the number of hours needed by all ages, divided into 9 age divisions. They're listed as ranges because gender has an influence, as well as lifestyle and health.
Newborns and Infants
Newborns don't have an established circadian rhythm; it isn't established until they're 2-3 months old. Infants tend to sleep in several phases throughout the day (polyphasic), sleeping from 2.5 to 4 hours at a time. By around 12 months, infants start sleeping more at night. At this point, they start to sleep more like adults in that there are no bodily movements during REM (rapid eye movement) sleep, which is when people dream. Prior to 12 months, babies will move during REM sleep.
Recognizing when school-age children aren't sleeping enough can be difficult as tired kids tend to not slow down, they speed up. They'll engage in behaviors that can resemble symptoms of ADHD. This includes resisting going to bed at night, even though they're tired. Student grades and attendance can also be a good indicator of whether your child is experiencing a sleep issue.
Children with ADHD can also be responsible for sleep disturbances, as well as other issues such as sleep apnea (when people stop breathing for periods throughout the night). It was previously believed that sleep apnea only occurred in adults, but now the American Academy of Pediatrics recommends screening for sleep apnea in children.
According to the Sleep Foundation, circadian rhythms shift after puberty, making teens want to go to bed after 11 pm and wake up later. Teenagers often have the earliest start times, such as getting up at 5 am to be at school by 7 am, which makes it rarer that a teen will get enough sleep. One study found that only 15% of teens reported sleeping 8.5 hours per night.
Because teens are sleep-deprived during the week they sleep more on the weekend, which can make the problem worse. One of the top recommendations from sleep experts is to fall asleep and wake up at the same time every day.
A problem that many teens share with adults is the use of back-lit devices late at night, which can prevent good quality sleep.
Lack of sleep in teenagers has a long list of drawbacks, including:
- drowsy driving leading to car accidents
- reduced emotional control, leading to more fighting with parents, siblings, and peers
- poor cognitive ability, focus, decision-making, and reaction time, leading to poor grades, athletic performance, and choices
- poor impulse control, which can create and strengthen bad habits
- skin issues such as acne
Adults tend to not get enough sleep for a list of reasons:
- stress from job and family
- consuming caffeine too late in the day
- looking at blue-light emitting devices within 90 minutes of going to bed
- inconsistent sleep schedule
- eating too late at night
- lack of exercise
- issues with the mattress: too hot, too soft or hard, and/or old
Depression rates among college-aged young adults (ages 18-25) are high, and this age group is the most likely to have serious thoughts about suicide, at 7.4%. Depression is often accompanied by life changes, and this period in life is often filled with changes. Sufferers of depression often experience insomnia, and the relationship between sleep and depression is complex. Those who suffer from depression may have trouble getting to sleep and staying asleep, and those who don't sleep enough are more likely to be depressed, creating a vicious cycle.
Anxiety is another condition that can prevent restful sleep. Anxiety rates are highest among middle-aged adults (ages 36-55), and anxiety is the most common mental illness in the U.S., with over 40 million sufferers, or 18.1% of the population every year. According to the Anxiety and Depression Association of America (AADA), over 50% of adults claim that anxiety affects their ability to sleep. And similar to depression, lack of sleep can trigger anxiety, and anxiety can cause a lack of sleep.
Many adults aged 65 and older nap during the day because they don't get enough quality sleep at night. One of the reasons they don't sleep well is because of medical conditions such as restless legs syndrome (RLS). It is estimated that 10-35% of seniors have RLS, which results in uncomfortable sensations in the legs creating an irresistible urge to move them. Symptoms occur in the evening and often during sleep. Around 80% of people with RLS also have periodic limb movement disorder (PLMD), and one study found that around 45% of all seniors have at least mild PLMD.
Many seniors also suffer from illnesses and take medications, both of which can disturb sleep.
Another common issue among seniors is that it takes them longer to go to sleep, with one study showing 13% of men over 65 and 36% of women taking more than 30 minutes to fall asleep.
According to the Sleep Foundation, seniors have trouble sleeping for several reasons. One is the change in the phases of sleep, where many seniors spend more time in the lighter phases of sleep and less in the deeper, more restorative phases.
Sleep fragmentation (waking up during the night) is also common, which greatly reduces the ability to wake up well-rested.
Women need on average 20 more minutes of sleep per night than men, though some women need even more than that. One theory for this is based on women multitasking more than men and having busier schedules, which results in their brains using more energy and therefore needing more recuperation. If this theory is correct, then men that have complex jobs that require a lot of decision-making and lateral thinking will need more than the average male as well. Another possible reason is the monthly hormone cycle that occurs with menstruation.
According to biomedical and social scientific studies, women do sleep more than men. However, several things can make it difficult for women to get enough quality sleep:
- Their male partners' snore (40% of men snore, as opposed to 24% of women)
- Stress from family and job responsibilities
Sleep Needs During Pregnancy
Pregnant women need more sleep, especially in their first trimester which leads to more sleepiness during the day. This is due to the rise in progesterone, as well as the metabolic changes that the body is going through.
They also are more likely to experience parasomnias, which are unusual behaviors that occur just before falling asleep, during sleep, or when waking up. Common parasomnias for expecting mothers are restless legs syndrome (RLS), snoring, and insomnia.
Expectant mothers in their first trimester will also have more frequent bathroom visits to urinate, due to the uterus pushing on the bladder. Swollen breasts, cramps, and nausea can also make it hard to fall asleep.
In the second trimester, women tend to sleep better as many of the changes have already occurred in the first trimester. However, it's not uncommon to experience leg cramps (often in the calves) as well as heartburn (due to the uterus pushing on the stomach).
In the third trimester, sleep gets worse again due to RLS, frequent urination, anxiety about the upcoming delivery, and lower back pain.
After the baby is born, new mothers will often find it easier to sleep because they're sleep-deprived. Babies are often awake every hour to few hours, so mothers can't get into the deeper, restful phases of sleep, so when they get a chance to sleep, the brain tries to make up the sleep deficit as quickly as possible.
Breastfeeding is sleep-inducing because the hormone that promotes lactation, prolactin, is a soporific, or sleep-promoting.
Can You Make Up Your Sleep Debt?
Some people believe that if they can't sleep enough for several days or more they can just make it up when they get around to it. For many people, on a short-term basis, that appears to be true. If you are sleep-deprived during the week, you may be able to make it up during the weekend.
However, with long-term sleep debt, the evidence isn't as promising. According to the Clayton Sleep Institute, research showed that six nights of sleep deprivation resulted in negative impacts on attention, daytime sleepiness, and inflammation. Even after a catch-up period to make up the sleep debt, attention levels didn't catch up. Cortisol, the prime marker for inflammation, didn't decrease either. A separate study showed that chronic sleep deprivation results in a loss of neurons which are responsible for alertness and cognition.
Another issue with sleep debt is that when you sleep too little then sleep a lot, your circadian rhythm is disturbed. Many sleep experts believe that to start sleeping better it is essential to fall asleep and wake up at the same time every day, regardless of whether it's a weekday or weekend. Have a regular sleep routine that leaves you well-rested, and there will be no need for a feast or famine sleep routine.
If you have a long-term sleep debt, experts recommend adding an extra hour or two of sleep per night with no alarm clock until you gradually start sleeping less.
It's also a good idea to make sure that you're getting the highest quality rest by following a good sleep protocol, which includes:
The Truth About Naps
A 15 to 20-minute nap can be a great way to help get rid of a sleep deficit. If you sleep longer than 20 minutes, you risk going into a deeper sleep and waking up groggy. The length of a full sleep cycle is around 90 minutes, so if you sleep for a full cycle you may not wake up groggy, though it may be more difficult for you to fall asleep at night.
Early risers tend to want to nap around 1 pm, and late risers an hour or two later. As long as you nap early in the afternoon, and not in the evening, it shouldn't affect your ability to sleep at night.
Many countries in Central and South America have afternoon siestas, as well as several countries in Europe. Research has suggested the fact that people want to nap around 1 or 2 pm in the afternoon isn't necessarily due to a blood sugar crash from lunch. The Romans in the 1st century B.C. used to divide their day into sections, and the period 6 hours after waking up at 6 am (noon) was for napping and called the "sexta" or the sixth hour after waking, which later became known as "siesta." Dr Sara Mednick, author of "Take a Nap! Change Your Life," says that our circadian rhythms are programmed for one long sleep at night, and one short one in the afternoon.
The first research into naps came from Jurgen Aschoff in the early 1950s in abandoned World War II German bunkers that had no natural light. Subjects stayed in the bunkers and were told to sleep whenever they felt tired, and they slept for one long period of 6 to 7 hours, then 12 hours later for a second period of an hour or less.
Dr Moira Junge, psychologist, and spokesperson for the Sleep Health Foundation in Australia, believes that people would be healthier if they took naps. She says that all human beings experience a post-lunch dip whether they've eaten or not. But what you eat can have a significant impact on the intensity of that dip. Eating a carbohydrate-based lunch will make the dip worse, whereas eating a protein-based lunch will reduce it.
Sleep Deprivation in Babies and Children
The younger a person is, the more sleep they require to help facilitate the development of a growing body and brain. According to the Sleep Foundation, when a child hasn't slept enough, they may not always slow down, but they may speed up. Their behavior may resemble the symptoms of ADHD, and they'll resist going to bed.
A few things that can help get a child to bed include:
- a bedtime between 7 pm and 8 pm
- a consistent sleep routine, such as brushing their teeth, reading a story, followed by lights out at the same time every night
- no sugar and caffeine in the evening
Signs of Sleep Deprivation in Adults
Do you know anyone that brags about not needing more than 4 or 5 hours per sleep per night? Have you wondered how much more work you could get done if you didn't need to sleep 7-9 hours per night? Do you belong to a company that looks at not sleeping as a badge of honor?
It turns out that lack of sleep can make you a lot less productive, and only rare people can be well-rested on 4-5 hours per night of sleep.
You may be sleep-deprived if you find yourself doing any of these things:
- wanting to sleep after eating
- falling asleep while reading or while watching TV
- hitting the snooze button multiple times in the morning
- "crashing" and sleeping for many hours on end once in a while
- relying on caffeine and sugar to keep your energy levels up
You can be sleep-deprived even though you are sleeping the recommended 7-9 hours per night because you're not getting quality sleep. If you have any of the following problems, you're probably not getting enough restful sleep:
- it takes you a long time to fall asleep once you go to bed
- you wake up multiple times throughout the night
- you wake up feeling tired
Sleep Deprivation and Weight Gain
Many people attribute their inability to lose weight to a lack of discipline. They feel guilty because they can't stick to a diet and exercise schedule, which can lead to emotional eating.
The reality for many people struggling to lose weight is that the lack of restful sleep impacts their brain's hormone production. When you don't get enough sleep, your leptin levels go down, and as leptin is the hormone that helps you feel satisfied and stop eating, you feel the need to continue eating.
In addition, your ghrelin levels go up, which is the hormone that stimulates your appetite.
As well as changes in ghrelin and leptin levels, researchers at the University of California Berkeley have found that when people are tired, they're more likely to eat foods that are bad for them. This can become a vicious cycle where you don't sleep well, so you eat more foods that are likely to be unhealthy, which in turn negatively impacts the quality of your sleep.
How to Get More Restful Sleep
If you suspect that you have a sleep disorder, it's best to talk to your doctor. But most people can look at a thorough sleep hygiene program and find at least a few aspects that they could improve on. Some of the most common mistakes that people make that reduce the amount of restful sleep are:
- exposing their brain to blue light from their cell phone, tablet, or TV within a few hours of going to bed. Blue light tells your brain that it's time to be active and blocks the production of melatonin, the "sleep hormone"
- consuming caffeine and sugar before bed
- eating too much before bed
- reading work emails in bed and/or working until bedtime
- having a stressful lifestyle
- going to bed and waking up at different times every day, which disturbs your circadian rhythm
- sleeping on a mattress that's too hard, too soft, or old. If you wake up with back or joint pain, you may be on the wrong mattress
- sleeping on a mattress that gets too hot
- having anxiety about how you will sleep, which can prevent you from sleeping well
- lacking in physical exercise, which is a great way to relieve stress and has been linked to better sleep
There are also a variety of mistakes people make with their posture and sleep position that can lead to a poor night's sleep, especially anything that prevents your spine from resting in a neutral position.
- Using a pillow that is too thick or too thin can lead to an under or over supported neck. Pillow thickness is especially tricky with side sleeping. You can read more about this in our side sleeping pillow guide.
- Sleeping on a mattress that is too firm or too soft or isn't a good match for your sleeping position. Back and stomach sleepers should generally seek out a firmer mattress while side sleepers generally need a softer mattress. You can learn more from our mattress guide for side sleepers.
- Ignoring leg position. Depending on how your legs are positioned they can have a dramatic impact on your hips and lower back. Back sleepers should consider elevating their legs. The best way to do this is with a foam wedge. Our favorite is the Ebung Foam Wedge which is available on Amazon. It pretty much eliminates the tension in your lower back by rotating your hips backward. Side sleepers should try to put a gap between their legs using a foam roll or a pillow for similar reasons. When your legs are touching the high leg rocks your hips and bends your lower back.
- Having an under supported lumbar or lower back is a common issue for back and side sleepers. Both can benefit from a lumbar pillow. Back sleepers only need a thin pillow and could potentially get away with a folded towel, while side sleepers usually need a thicker pillow. We created an in-depth guide on lumbar pillows for sleep, check it out.
Sleep Needs Frequently Asked Questions
Table of contents:
- The Importance of Sleep
- How Much Sleep Do We Need?
- Sleep Needs During Pregnancy
- Sleep Debt
- Sleep Deprivation in Babies, Children, and Adults
- Sleep Deprivation and Weight Gain
- How to Get More Restful Sleep
- Sleep Needs FAQ