Getting a good night’s sleep is highly important in order for our brains to function well. However, at times it can be difficult to get a sufficient amount of sleep, particularly with the stressed and busy lifestyles that most of us have, leading to numerous health hazards. Below we give a brief background on sleep and present tips that are backed by science on how to help us improve our sleep habits.
Why Sleep Is Important
On average, adults spend 36% of their lives asleep. Sleep can be identified due to fluctuations in our brain waves, and other changes in our bodily functions, for example, temperature and blood pressure levels and the production of certain hormones. In particular, digestive and cell reparation activities exhibit a maximum during sleep.
Sleep is necessary on many levels. Firstly, while we sleep, our brain gets rid of the metabolic waste (products left over from metabolic activities) that we have built during the day. A large build up of such waste products has been associated with Alzheimer’s disease and other neurological disorders. Our brain is two times more effective in getting rid of this waste when sleeping compared to waking hours. This is because when we sleep, our brain cells are reduced by 60%, allowing the brain to get rid of its waste using the glymphatic system, in a much easier way. In addition, sleep is crucial for our long-term memory.
Not enough sleep, or not sleeping continuously, prevents us from establishing memories. Sleep is also essential for our metabolism. It has been shown that sleeping for 5.5 hours at night (instead of 8.5 hours) causes a smaller percentage of the energy that we burn to come from fat, and a greater percentage to come from carbohydrates and protein. This can influence how much fat we gain and how much muscle we lose. Not getting enough sleep has also been associated with an increase in diabetes and heart disease. Studies suggest that adults need between 7 and 9 hours of sleep each night to function well. This increases for children and the elderly. This is enough sleep to raise energy levels, and decrease risks of type 2 diabetes, heart disease, obesity, and depression.
The effect of not sleeping enough increases over time if carried on, i.e. if there is sleep debt. It has been found that sleep debt has a neurobiological effect that will build up over time. Studies have found that those who experience severe sleep debt are unaware of their rapid performance decline.
Most of us try to “catch up” on sleep when we get the chance. Studies show that sleeping more on the weekends reduces some of the effects of a lack of sleep, such as feeling sleepy during the day, or inflammation. However, other effects, such as those relating to cognition, such as memory, focus, and attention, are not reduced. Hence, the only way to keep our cognitive performance in balance is to sleep well at night. This does not mean to say that we should never try to catch up on sleep; it is always advisable to try to get some extra sleep if you need it.
The Sleep Cycle
The sleep cycle is divided into two phases:
- Slow wave sleep, or deep sleep.
- REM (Rapid Eye Movement) sleep.
During the first phase of the sleep cycle, we become more relaxed. Our breathing becomes more regular, blood pressure is lowered, and it becomes more difficult for our brain to respond to sounds and movements. During this time, body renewal processes occur, as the pituitary gland produces a growth hormone for muscle repair and tissue growth. Studies show that during this phase, our immune system is also repaired. The second phase of the sleep cycle is focused more on the repair of the mind. During this time, we also dream. REM sleep allows the brain to improve the memory, clear out information that is not necessary and aid in the processes of neural growth and learning. REM occurs on average 3-5 times a night, for a short period of time on each occasion. During this time, our blood pressure, heart rate, and body temperature all increase.
Without these two phases of sleep, our body and mind will break down. Our brain will not be able to function properly, nor will our immune system. A severe lack of sleep results in a rise in the risk of diabetes, viral infections, weight gain, heart disease, mental illnesses and high blood pressure.
The sleep cycle is controlled by the circadian rhythm, a biological cycle of various processes and activities that last for 24 hours. For example, when we wake in the morning, melatonin production stops, and in the evening the production of melatonin starts again to get the body ready for sleep. Melatonin is a hormone that we produce that makes us feel drowsy and regulates our body temperature. The circadian rhythm is itself controlled by light, time and melatonin. We use it to help us regulate when we feel sleepy and awake. Most of us have a peak in sleepiness between 1-3pm, after lunchtime, and then between 2-4am, although this is a generalization and depends on each person, which is why some of us feel more awake in the morning and others in the evening. In general, reading and following the natural indications from our body on when to sleep and wake up, will ensure that our circadian rhythm is balanced. However, in the modern world, we come across many disruptions, such as changes in our daily schedule.
Considered the most important regulator, light has the power to reset the circadian rhythm, irrespective of the time of day. Usually, this happens with the rising of the sun, but can also occur with a bright light. Our day to day schedule, including the time and order we do things, influences our sleep cycle.
During the last few million years, humans developed to be awake when there is daylight and sleep during the night. Yet, nowadays we have a more distorted sleep pattern. Most of us spend the day working inside, where low levels of daylight enter, and we end up using bright screens (phones, computers, televisions) at night time. This is opposite to the pattern of our ancestors and plays havoc with our sleep cycle, and causing us, for example, to feel drowsy and with a lower productivity. Hence, the basic steps we can take for us to sleep better are ensuring that we get lots of daylight during the day and using low lights during the night.
Research has shown that the time we go to sleep affects how we sleep. The proportion of deep sleep to REM sleep varies throughout the night, with deep sleep occurring more during the earlier part of the night and REM sleep more towards dawn. Hence, going to bed later could mean losing out on crucial deep sleep. Scientists say that the best time to go to sleep is between 8 pm and 12 pm, with the exact time depending on the individual.
How To Sleep Well
As mentioned above, the bright light from out telephone screens etc. affects our sleep cycle as it slows down the production of melatonin. In particular, it is the blue light of the light spectrum that affects melatonin production. Also, working until the late hours does not help our sleep pattern as we tend to go to bed stressed and thinking about work. It is much more beneficial for our sleep to shut down all screens a couple of hours before going to bed and read a book instead. In addition, it is important to be relaxed at bedtime, with studies showing that more than 50% of insomnia is initiated by emotional or stress related causes. Release stress during the day, with activities such as exercising, deep breathing, and meditation.
Sleep intensity relates to how much time we spend in deep sleep and in REM sleep. There is not much that we can do to change our sleep intensity. Our body usually regulates this depending on how much we are sleeping. However, we can work on when we go to sleep, and how long for. The time that we go to sleep is important for our sleep pattern. Going to sleep at the same time each night helps our body get into a sleep routine. Also, the time we go to sleep should follow our circadian rhythm. Assuming that we are able to wake up at the same time every morning, then an earlier bed time means more sleep. Going to bed and waking up later than usual on the weekends makes it more difficult for us to sleep on Sunday night and get up on Monday morning.
Below we present practical tips on how to improve our sleep cycle.
- Try to be outside for at least 30 minutes each day to see daylight and sunshine. It is particularly recommendable to go for a walk in the morning as this resets our circadian cycle.
- Make sure to lower the lights inside when it’s dark outside, particularly the blue wavelength light, as this confuses the brain into thinking it’s daytime still and prevents it from producing melatonin. Using low red lights in the evening is more advisable.
- As already mentioned, exercise helps us sleep better, as it helps our mind and body relax before sleep. Also, exercise helps with obesity, which can mess up our sleep cycle. Exercise also gives us more energy and reduces depression, as well as helping with sleep apnea and restless leg syndrome. The former causes sufferers to stop breathing momentarily while sleeping, and the latter is associated with the involuntary movement of the legs and other parts of the body, as well as itchiness and burning. It is important to note, however, that it is not advisable to exercise 2-3 hours before you go to sleep, as this actually makes it more difficult for us to relax at night due to the temporary increase in hormones and neurotransmitters caused by exercising.
- Get rid of any caffeine, and if you cannot survive without coffee, make sure that you do not have any after midday. Caffeine changes the amount of melatonin in our brain, this makes it more difficult for us to fall asleep and may make us sleep less.
- Also get rid of tobacco, as it has been linked to sleep problems. Nicotine is a stimulant, which can make it more difficult to go to sleep or increase chances of waking up at night. In addition, smokers are more at risk of sleep apnea, as smoking causes inflammation in the nose and throat and the excess production of mucus, blocking the airways.
- Alcohol can make us fall asleep quicker, this is because it works with the GABA (gamma-aminobutyric acid) receptors. These are neurotransmitters that lower nerve activity. However, alcohol also affects sub-receptors that make us feel sedated, not sleepy, taking it longer to get into our REM sleep cycle. This is why often, after drinking the night before, we feel tired after waking up, despite sleeping a lot. It is advised to have your last drink at least three or four hours before you go to bed, to allow the body to metabolize the alcohol.
- It is advisable to sleep in a cool room; around 18oC or 65 o This is because our circadian cycle changes our body temperature as the day progresses. At bed time, our body temperature drops. We experience a drop of 3 oF during the deep sleep phase of our sleep cycle.
- A peaceful and quiet room is essential for a good night’s sleep. White noise can help drown out loud noises.
- Try to limit the activities that you perform in the bedroom, for example, no laptops, TVs, and other distractions. In addition, studies suggest that going to sleep with someone that makes you happy helps you sleep better.
- As mentioned above, going to bed stressed makes it more difficult for us to go to sleep. To help our mind feel more relaxed, it is advised to imagine calm, pleasant images, as well as listening to music.
- It has been shown that feeling that life has a meaning or purpose improves our quality of sleep. This can be aided with activities such as therapy and meditation.
For those that have persistent insomnia that does not go away, there may be an underlying condition involved It is advisable to visit the doctor in this case. However, caution should be taken when sleeping pills are administered. Although they can be very effective, they can also have side effects, such as infections and dementia in the elderly population. They also do not work as well after a few weeks.
Although most of us skip sleep to work more, we are actually less productive at work due to the lack of sleep. It is much more beneficial to focus on sleeping well, which will, in turn, ensure higher productivity at work. As well as following the tips above to reduce sleep related problems, it is important to determine what is best for you, as each person has their own unique way of relaxing.