Why is sleep a need?
Sleep is an active and involuntary process in which our body performs a series of essential activities. Sleep is vital for our body, especially for our brain, which is in charge of processing information, consolidating memory and enabling us to function the day after with new insights and creative ideas. Without sleep, we cannot operate effectively, and we risk problems ranging from lack of concentration to even death. We need to understand the overall process to ensure the right quantity and quality of sleep. For specific sleep disorders, consult a specialist.
What is sleep?
Sleep is driven, from a biological standpoint, by two main factors:
- The sleep pressure, controlled by a mechanism in our body called sleep homeostat. From the moment we wake up, and throughout the day, the sleep pressure increases until being released at night, when we sleep. When a sleep debt exists, sleep pressure gets higher. If we have under-slept for several days, the debt will have to be paid in more extended periods; if no sleep debt is present, we will be able to pay it night by night.
- The body clock that regulates the circadian rhythms. The circadian rhythm is an approximately 24-hour cycle mainly regulated by light and dark cycles. The body clock, made of nerve cells located above our optic nerves, sends signals from our eyes to the brain. It is when there is not so much light, such as at night, that the nerves produce melatonin, a hormone that makes us feel sleepy. Is for this reason that at the time of sleeping it is recommended to turn the lights off. Although today we have the chance of turning on the lights and continue working long after dinner, humans are not conceived to be awake during night. People who regularly work night shifts are thought to be at a higher risk of cancer and heart disease.
Once asleep, we go through different stages, all part of a sleep cycle that we (adults) should repeat between four and five times per night. The number of sleeping cycles experienced each night is different for everyone, depending on age, habits and specific conditions. Each sleep cycle lasts between 90 and 110 minutes composed of four non-REM stages, accounting for the 75-80% of our sleep time, and one REM stage:
1. The first non-REM stage. This stage represents the transition between being awake and sleeping. Therefore, it is considered light sleep. In fact, during this stage, the sleep is very light, we can be awakened easily, our breath and muscles activity slows down, and we may experience some muscular spams, known as hypnic jerks.
2. The second non-REM stage. During this stage, still considered light sleep, both breath and heart rates slow down, body temperature decrease and eye movement stop. The brain produces sleep spindles, sudden increases in brain wave frequency then slowed down. This is the stage to target as a wake-up point if you want to have just a power nap.
3. The third and fourth non-REM stages. These two stages are usually grouped in one, and they are known as deep sleep. At this stage breath and heart rates reach their lowest levels, muscles activity is limited, and the brain begins producing slower delta waves making this the stage when it is most difficult to wake us up. The body repairs muscles/ tissues, stimulates growth, boosts immune function and creates energy for the upcoming day.
4. The REM (rapid eye movement) stage. During this stage, both breath and heart rates rise, the brain becomes more active, the muscles relax, and the body paralyzes, eye movement is present, and dreams occur. The brain consolidates and processes information from the previous day so that it can be stored in our long-term memory.
To perform the recommended number of sleep cycles every night is important to provide ourselves with the proper amount of sleep hours, not confusing time spent in bed with time asleep. When getting old, the number of times that we awake during the night increase, decreasing, therefore, the sleep efficiency. To enhance the chances to perform the proper number of cycles, here are some recommendations of needed asleep time by age:
1. New-borns (0-3 months): 14-17 hours.
2. Infants (4-11 months): 12-15 hours.
3. Toddlers (1-2 years): 11-14 hours.
4. Pre-schoolers (3-5 years): 10-13 hours.
5. School-aged children (6-13 years): 9-11 hours.
6. Teenagers (14-17 years): 8-10 hours.
7. Young adults (18-25 years): 7-9 hours.
8. Adults (26-64 years): 7-9 hours.
9. Older adults (>64 years): 7-8 hours.
It is always important to be aware of how we feel and adjust the amount of sleep to meet our needs. If worried about the quality of your sleep, it is recommended to consult a specialist.
Why is sleep important?
The importance of providing our body with the recommended hours of sleep lies in enabling it to perform the needed set of sleep cycles and therefore spend the required time in the two beneficial stages of sleep: deep sleep and REM sleep. While sleeping, our brain catalogues the previous day’s experiences, primes our memory, and triggers the release of hormones regulating energy, mood, and mental acuity. In particular:
- Deep sleep is crucial for physical renewal, hormonal regulation, and growth. Deep sleep deprivation potentially leads to a higher risk of getting sick, feeling depressed and gaining weight.
- REM sleep is crucial for learning, and higher-level thought, since in this stage, the brain processes and synthesized memories and emotions. REM sleep deprivation potentially leads to slower cognitive/ social processing, issues with memory and focus.
Looking, for example, at deep sleep from a more scientific standpoint, a consistent loss on its 1.5 target hours per night(for adults) impacts on:
- The human growth hormone (HGH), an essential part of the body's endocrine system, released by the brain into the bloodstream during sleep to repair and restore the body. It aims to promote growth in childhood and to help maintain healthy body tissue during adulthood.
- The glymphatic system, mainly active during sleep, makes cerebrospinal fluid flow through the brain tissue flushing out waste, such as proteins. Since sleep often becomes lighter and more disrupted growing older, research studies have reinforced the links between ageing, sleep deprivation, and heightened risk for Alzheimer's disease.
- The natural killer cells (NK), a type of cytotoxic lymphocyte with a substantial role in killing tumour cells. Their activity can be reduced to an average of 70% when restricting the time allowed for sleep to 4 overall hours for one night.
In general, scientific evidence suggests that sleep loss could be a significant factor contributing to a wide variety of disorders.
What prevents proper sleep?
When sleeping well, we shorten the length of our deep sleep stages at each cycle: from approximately 40 minutes in the first cycle to zero in the fifth cycle (flowing through about 30 minutes in the second cycle and about 15 minutes in the third cycle). The sum of all stages adds up to the 1.5 hours of deep sleep that our body needs to function (for adults) properly. REM stages instead get longer and longer overnight.
Unfortunately, this sleep pattern is not always true in reality. Several roadblocks lead us to poor sleep performances: we experience a lighter in sleep during first cycles and only around fourth or fifth cycles we somehow manage to achieve a few minutes of deep sleep. This translates into lower energy, inconstant focus, mental unclarity and declining performances.
Roadblocks come in different forms, such as:
- The environment we sleep in, for example, our bedroom might be too noisy, too light or not right in temperature.
- The activities we perform before sleep, for instance, heavy late workouts.
- The intakes we have before sleep, for example, late consumption of heavy meals, alcohol, caffeine or even water.
- The levels of tryptophan, an amino acid that increases serotonin which also improves melatonin and therefore affects sleep and mood balance.
Only a consistent tackling of each of the possible roadblocks will lead us to sleep well, achieving the required amount of deep sleep to function properly.
How we sleep impacts on our body in many different ways. Poor sleep may, for instance, weaken the immune system, increase blood pressure and heart rate, boost the risk of type 2 diabetes, enhance vulnerability to respiratory infections and affect different hormone production.
There is a bi-directional relationship between sleep and mental well-being. Poor sleep may be a sign or the result of an existing psychological condition. Still, it may also cause or contribute to the origin of several mental disorders, including depression and anxiety.
The less sleep we get, the less we want to interact socially. Sleep deprivation, according to researchers, makes us less sensitive to other people. In essence, it reduces our brain’s ability to read emotional signals of how we affect others and to decide how to respond in socially appropriate ways.
1. Sleep in multiples of 90 minutes. Do not wake up while you're somewhere in the deeper levels of the sleep cycle, rather when the body is naturally primed to wake up. Furthermore, by interrupting the cycle, your body resets it all over again, not reaching the restorative part of it, typically at its latter part.
2. Achieve 1.5 hours of deep sleep per night. Focus on how much deep sleep you can extract from your asleep time. Aim at 1.5 hours of deep sleep per night (for adults), and this is the only way to let sleep perform its potent health benefits.
3. Follow a schedule. Set-up a unique schedule with sleep and wake-up times to be followed even during the weekends. This means to set an anchor to get-up time (and by backward planning also a go-to bed one) that will eliminate the random nature of sleep and therefore strengthens your internal body clock. To find your anchor get-up time is essential to analyse your last three months of work and private life and figure out what is the earliest time you have been getting up (not considering exceptions): that will be your new target. Start, at first, with the help of an alarm and then dismiss it leveraging on a strengthen internal body clock. Once your anchor get-up time is clear, you need to discover your related go-to bedtime: to do so you only have to calculate backwards, from your anchor get-up time, four to five sleep cycles of 90 minutes each and, to add on top, the usual time required to fall asleep. That's your ideal go-to bedtime. For example, if your anchor get-up time is 6:00 AM, you calculate backwards five sleep cycles of 90 minutes (for total sleep duration of 7.5 hours) reaching 10:30 PM; on top of that, you add 15 minutes as a time to fall asleep, reaching 10:15 PM as your go-to bedtime.
4. Focus on cycles per week, not hours per night. Our work and private life require us sometimes to manage sleep with flexibility. Anyway, to keep consistency, we can switch our focus from the single day to a longer planning horizon which is the week. In this way, we can better balance days with a lower amount of sleep cycles with those richer. Although the golden rule remains to go to bed and wake up always at the same time, in case of unbalanced evening plans the rule of thumbs for the weekly levelling is to stay at least between 28 and 30 sleep cycles per week. This rule requires anyways to avoid extreme drops in sleep time: try to get at least four nights per week with five cycles as well as try to prevent three consecutive nights of less than five cycles.
5. Follow a bedtime routine. Use the hour before going to sleep to relax (for instance, with a warm bath, not hot) or to do a calming activity (such as reading).
6. In your bedroom, avoid anything that prevents you from falling asleep or that can disturb your sleep. In terms of technology, avoid TVs, computers, phones and tablets. It has been proven that sending or receiving calls and messages after lights have been turned off and being woken by other phone use is associated with tiredness and lowered mood.
7. Do not worry. If you do not fall asleep within 20 minutes of having gone to bed, get up and move to another area of the house where you can read or listen to an audiobook. You can even get some fresh air or write down what’s on your mind. Do not check your phone nor expose your eyes to bright lights. Go back to the bedroom only when you feel sleepy; in this way, you will not alter the mental association between bedroom and resting.
8. Manage naps. Although up to 26 minutes naps can help to improve mood, performance and alertness, taking them too late in the afternoon can alter your sleeping patterns. Avoid napping more than 30 minutes, unless you need to catch up deep sleep, then go for a longer nap of 90 minutes, equal to one full sleep cycle.
1. Avoid caffeine and nicotine. These stimulants can disrupt your sleep, especially if consumed close to bedtime. Remember that caffeine can be sourced not only in coffee but also in tea, energy drinks and chocolate. Target around 400 milligrams of caffeine per day, with the last intake about 8 to 9 hours before sleep.
2. Limit alcohol consumption. While it can help you at the time of falling asleep, it can disrupt sleep in the second part of the night, limiting our ability to reach deep sleep. When the alcohol wears off in the middle of the night, we are more prone to wake up due to the signals sent to our brain and the boosted need to urinate.
3. Limit liquid consumption. Avoid drinking too much 2 to 3 hours before sleep if you want to eliminate potential comes and goes to the bathroom.
4. Avoid big meals at night. Heavy, spicy and acidic foods should be avoided within 2 to 3 hours before going to bed. This because of the heavy digestive activities in which our body is involved, prevents us from falling asleep. If you really can't help to avoid late intakes, only if necessary, try sleepy snacks such as almond butter or low-fat milk/ cheese.
5. Avoid refined carbohydrates and sugary foods. Eating lots of white bread, pasta and rice during the day can reduce your sleep.
6. Consider eating a specific food. Eating foods that contain melatonin (like walnuts, almonds, cherries, bananas, raspberries, etc.) can shorten the time needed to fall asleep while decreasing the number of times that you wake up during the night. Eating foods high in tryptophan (like potatoes, grains, cottage cheese, etc.) may increase serotonin levels (low levels of serotonin on our brain can lead to sleep disorders like insomnia), which then increases melatonin as well. Tryptophan is assumed to be safe in reasonable quantities: it’s estimated that a typical diet contains from 0.5 to 1 gram per day. Some individuals choose to supplement their diet with doses of tryptophan up to 1.5 grams per day, as a sleep enhancer, or even 3 grams in the evening, as a sleep accelerator. If you are considering to supplement your diet with tryptophan, consult a specialist.
1. Exercise. Staying active every day improves your sleep and keeps you awake during the day. The more you train, the more you benefit your sleep. However, a light aerobic activity like 10 minutes walking or cycling can have a positive impact as well. Although it changes from person to person, try to exercise in the morning or the afternoon as heavy-close-to-bedtime-workouts can interfere with your sleep. This is due to the elevated level of carbon dioxide in our blood as well as the high heart rate resulting from such an activity. If you really can't help to move in the evening, then allow yourself only regenerating sessions.
1. Keep your bedroom free of air pollutants. Tracking and eliminating different toxins and pollutants that we inhale while sleeping, like dust, pollen and mould, can improve our breath and decrease the chances of developing allergies and other diseases like obtrusive sleep apnea.
2. Keep your bedroom neither dry nor humid. Too much humidity can make it difficult to fall asleep, generate mould and increase the risk of developing allergies. At the same time, breathing dry air can lead to irritated nasal passages and throats, sore lips or sneezing making in turn more difficult to fall and remain asleep. Keeping the bedroom between 30% and 50% of humidity creates an environment in which it is easy to breathe, and it is not too muggy.
3. Consider using pure essential oils. Using scents when going in bed can relax and help you on falling asleep. As well, it can promote a mental association between the scent and resting.
1. Expose yourself to natural light. Try to concentrate the outdoor activities during the day and let natural light come into your home or office as much as possible. This helps you with maintaining your sleep-wake cycle.
2. Keep your bedroom dark. At the time of sleeping, make sure that light does not enter your room. You can use an eye mask when travelling or in hotel rooms to recreate the same darkness scenario. When in hotels, unplug (or mask with black tape) all electronic devices that emit rays of light.
3. Avoid exposure to blue lights. The light emitted by smartphones, tablets, computers and TVs increases alertness and can delay the release of melatonin. Fluorescent lightbulbs and LED lights can produce the same effect. It is then advised to avoid the exposure between one and two hours before bedtime. If not possible, then decrease the brightness or move from blues to warmer colours like reds and yellows when daylight fades. Another easy remedy is to wear blue light blockers glasses about 3 hours before sleep.
1. Keep your bedroom quiet. The calmer your bedroom, the higher the quality of your sleep. Even if you fall asleep quickly in a noisy environment, your mind remains in alert mode, and you stay in the stages of light sleep without entering into the restorative deep sleep stages. You can use earplugs when travelling or in hotel rooms to recreate the same quiet scenario. When in hotels, ask for a room far away from the elevator and the stairs, ideally at the end of the floor.
1. Keep the bedroom cool. Humans are endotherms able to regulate the body temperature and to keep it between a small range around 37°C. The body reaches the highest temperature in the evening, before preparing for sleep, and the lowest temperature just before waking up. Keeping a cool temperature in the bedroom, neither too hot nor too cold, helps the body to regulate its' temperature and facilitates deep sleep. The best temperature for sleeping is between 15.5° and 19.5° for adults, and between 18° and 21° for babies and toddlers. When in hotels, cool down the room at your arrival.
1. Sleep on comfortable mattresses and pillows. A good rest depends as well on the bed you use. Choose the mattresses and pillows that better suit your weight and sleeping style. If you have been using a mattress for more than seven years and a pillow for more than two years, it might have come the time to renew them.
1. Manage temporary sleep problems. In the case of temporary sleepiness, non-drug therapies can help mitigate sleeping difficulties and reset the circadian clock. Please consult an appropriately qualified and licensed physician or other health care provider for medical advice.
2. Reach out for medical advice if affected by sleep disorders. Please consult an appropriately qualified and licensed physician or other health care provider for medical advice if you suspect or know to be affected by a sleep disorder. For example, in the case of diagnosed sleep apnea, the commonly used treatment is Positive Airways Pressure therapy or PAP therapy (either CPAP, BiPAP or APAP). The associated machines provide the patient with a stream of compressed that supports his/her airways during sleep. Please consult an appropriately qualified and licensed physician or other health care provider for medical advice. Aside from PAP therapies, medical therapies can sometimes be prescribed by doctors to treat other sleeping disorders such as Insomnia, Sleep-related movement disorders, Hypersomnia and more.
1. Recognize your baby sleeping readiness signs. It is important to recognize signs of sleep readiness from your baby to teach him/ her consequently to fall asleep autonomously; typical symptoms are rubbing the eyes, yawning, looking away and fussing.
2. Create a sleep routine. Like adults, babies need a routine to sleep better. Unlike adults, they have to rely on you to provide consistency to their bedtime routine, including your responses to different events. For example, you could think of a routine such as: taking a bath, reading a book and then rocking. No stimulation or energetic activity close to bedtime is suggested.
3. Help the shift towards sleep. Often, playing soft music or relaxing sounds (like white noises or shushers) can help your baby to fall asleep. Another support can come from a transition object that your baby can take with him/ her to bed, such as a small blanket or a soft toy (attention, to avoid suffocation risk, don’t do this before your baby is old enough to be able to roll and sit).
4. Monitor and manage night awakenings. Either you hear it for yourself or through the help of a monitor when your baby awakens, you can pat and soothe him/ her to reassure him/ her and help transition back to sleep. If he/ she keeps crying, repeat this comforting procedure at intervals of a few minutes, coming and going from his/ her bedroom. It is not advised to take him/ her out of bed, instead use bassinets and swings that make gentle rocking motions.
1. Understand how sleep architecture change with age. The required sleeping time decrease as we age reaching its stabilization around the age of 18 when the needed sleep level balance between 7 and 9 hours per night. From that age on, we need the same amount of sleep hours, though sleep architecture changes. The neurons that regulate sleep patterns in elderlies' brains begin to die, making it more difficult to fall asleep, to spend more time in deep sleep and to avoid more frequent awakenings. For this, it is even more crucial to implement all the sleeping best practices already suggested for adults in general, such as sleep routine, light sleeping, proper drinking, reduced stress levels and adequate movements.
2. Manage arising sleep disorders. Insomnia, with its struggles in falling and staying asleep, sleep apnea, with its lapses in breathing, and sleep-related movement disorders, are some of the causes that can disrupt elderlies' sleep. Specialists can diagnose and limit the impacts of such disorders. For example, insomnia can be treated with cognitive-behavioural therapy, relaxation techniques, natural sleep aids like melatonin or, in some cases, just by introducing a set of healthier habits. Sleep apnea instead can be treated with the continuous positive airway pressures (CPAP) therapy, which implies sleeping with such a machine all night long to minimize the risks, for example, of stroke, memory loss or high blood pressure. There are specific solutions for each of the sleep-related movement disorders, among which can be listed the restless legs syndrome, the periodic limb movement disorder and the REM sleep behaviour disorder. These and the previously presented disorders need a specialist to be treated appropriately.
3. Ensure bedroom safety. To prevent injuries and to ensure more restful sleep, all potential hazards need to be managed with risk mitigation solutions. Among all, night falls and wandering are the two most common criticalities. Simple items such as throw rugs, clutter and power cords can transform themselves into night falls triggers. Removing them as well as improving lighting solutions can help the elderly to move around during night time safely. Different safety precautions should be taken in case of the wandering, common symptom of dementia or Alzheimer's disease: in this scenario, hazards are not only present inside the home but especially outside since these people can walk or drive elsewhere in a disoriented and confused state of mind.