Why sleep?

    By the end of our lives, we will have spent 1/3 of our time sleeping. Sleep is a fundamental human need, but more than half of Canadians report that they cut back on sleep when they need more time to accomplish more during the day. One-third of Canadians sleep fewer hours per night than the recommended number. Yet, sleep is a valuable ally for physical and psychological health as well as for the prevention of health problems. There is still a long way to go to ensure that the need for sleep is recognized by public and health professionals and for it to be considered a critical determinant of health.

    Sleep, nutrition and exercise are all critical for health and hygiene. However, if one or more of these pillars are consistently neglected because of poor lifestyle choices our daily life is affected in the long term.

    As a pillar of health, sleep does not just make you feel fresh and restored in the morning, we sleep to conserve our energy, and to refuel it daily, However, the sleeping brain accomplishes much more. It is known that even though the body works to conserve energy during sleep, its cells still actively regulate essential brain and metabolic activities. Many scientific studies focus on the role of sleep and several precise mechanisms have been identified over the years to help us understand its usefulness. These studies demonstrate how active the brain is when sleeping, and help define the role and complementary functions of the different sleep stages.

    We sleep for example to memorize and learn. Thus, while sleeping, brain cells (ie neurons) are busy consolidating memories and learning, sorting and storing all kinds of experiences we had during the day. This makes sleep a fundamental ally in the learning process. It is equally important for emotions and stress management, which is also harder when sleep is lacking (which you have probably already experienced!). Sleep plays a role in the preservation of the immune system and helps to regulate almost all the functions of our body: from the brain, heart and lung activity, to metabolism and the endocrine system. During sleep, the brain also removes the metabolic waste it produces during the day. It is also during slow waves sleep when the growth hormone is secreted in children and adolescents.

    The impact of reducing sleep time on a daily basis

    Let’s be honest: it is not always easy to maintain a healthy lifestyle and our sleep hygiene gets neglected at times. For example, the effect of pulling an all-nighter or voluntarily cutting back on sleep is often viewed as benign or without consequences. There are many reasons out of our control for shorter nights of sleep. Work schedule and child and family care are just two examples of responsibilities that can directly affect our sleep hygiene.

    Although reducing sleep time is often considered a short-term “solution”, with little impact beyond fatigue, the accumulation of a serious and chronic sleep deficit will have a multitude of effects on your physical and psychological health. Moreover, a sleep deficit does not just accumulate during one sleepless night, but also increases each time a night is shortened and you sleep less than your body needs.

    If you continue on that road, you will soon feel the harmful impact of sleep deprivation.

    For many reasons, some of us consider that cutting back on sleep is a normal price to pay to have productive days or are willing to take the risks associated with sleep loss, but many are unaware of the consequences that this sleep deficit can cause. Did you know that cutting down your sleep can often be counterproductive in the long run?

    Sleep deprivation affects your mood and can make you irritable and sleepy. It impacts your brain, can increase pain perception, hinder memory consolidation mechanisms, and make you inattentive. It can also exacerbate existing physical and mental health problems and create ripple effects on the other pillars of health.

    Here’s an example, which may sound familiar, on how you could be vulnerable to sleep deprivation. You need to spend more time at work or you are studying for exams, so you decide to cut back on sleep to “gain” time. This sleep loss is the first step on the road to sleep deprivation.

    Then when the weekend comes, you’ll want to sleep more. This is generally good in the short-term for your sleep deprivation, but it will disrupt the regularity of your sleep schedule even more. Irregular sleep patterns mean your body can be out of sync with itself which in turn will negatively impact your sleep quality and may lead to symptoms of insomnia. Another toll on you.

    Over time, sleep deprivation will have a negative impact on the other pillars of health and may affect your ability to maintain a healthy diet and/or the practice of regular physical activity. For example, sleep deprivation disrupts your glucose regulation, making you crave carbohydrates (sugary food). Late meals or snacks and high sugar consumption will in turn further disturb your sleep quality. Sleep deprivation also has an impact on mood and motivation, which could impact the frequency of your physical training or stop you from initiating one. This decrease in physical activity will in turn have adverse effects on the quality of your sleep, which will further increase sleep deprivation.

    All these cumulative effects as well as the accumulation of stress and an inability to manage your emotions related to sleep deprivation could eventually lead to insomnia problems, such as difficulty falling asleep at night, fragmentation of your sleep or the inability to sleep for long periods of time at night.

    Here are several good reasons to prioritize your sleep and restore balance in the long term! Tips to help you in this direction can be found at the end of this article.

    The “naked truth” about the harm of sleep deprivation.  

    Consequences of sleep loss (e.g. repeatedly sleeping fewer hours per night than you need to feel rested)

    After a few nights… After a while…
    Yawning, fatigue, headaches
    Severe fatigue and headaches
    Sleepiness * SLEEPINESS VERSUS FEELING FATIGUE Sleepiness is the urge or need, difficult to repress, to sleep during the day. Not to be confused with fatigue, which is a feeling of exhaustion that requires one to rest, but that does not translate into involuntary sleep or an excessive need for it. Tired people can fight sleep without difficulty during the day. Sleepy people, on the other hand, are consumed by sleep. They can fall asleep easily in class, at work or while driving, for example. Sleepiness is not a normal state because it is related to either an acute (sleep deprivation) or chronic sleep loss or poor sleep quality. Severe sleepiness is often a critical symptom of sleep disorders, but also of certain medical or psychological problems. Don’t sleep on it!
    Severe daytime sleepiness with “sleep attacks.” At night, symptoms of insomnia, stress or fear of going to bed and not falling asleep (sleep anxiety), loss of sleep quality.
    Weight gain due to hormonal deregulation controlling the feeling of hunger and fullness
    Increased risk of Diabetes Obesity Cardiovascular diseases
    Glucose deregulation. Carbohydrate cravings. Hungrier, apt to eat more and make less healthy food choices.
    Higher blood pressure
    Reduced immune function, e.g. more likely to catch a cold
    Increased risk of cancer (colorectal, breast)
    Less cell regeneration of the hair and skin cells – looking tired
    Premature aging of the hair and skin and reproductive system (fewer sperm count)
    Irritability, lack of patience, stress, lower sex drive
    Increased risk of anxiety, burn-out and depression
    Difficulty focussing and staying attentive, forgetfulness – impact on school and work performance
    Attention deficit and memory loss – major implications for school and work performance
    More likely to have an accident with a motor vehicle or crossing a street or at work
    More likely to fall asleep while driving and have poor reflexes behind the wheel – major safety issues
    Increased mortality

    Lifelong and day-to-day key actions to prioritize a healthy sleep

    1. Respect a regular sleep-wake schedule

    Our body and brain respond well to routine and this is partly because of our biological clock. Here’s how to ensure a healthy sleep-wake schedule: Try to go to bed and get up at the same time (+/- 30 minutes) every day of the week (yes, even on week-ends!).

    During the day don’t forget to expose yourself to light as much as possible to also help your body clock keep time.

    2. Prioritize quality sleep, in sufficient quantity and in one session

    In order for the brain to recharge and do its night work properly, you need to sleep enough (in quantity and quality). To do that:

    • Sleep the amount of time you need within the age-appropriate recommended sleep time. For example, school age children need 9 to 11 hours of sleep per night; teenagers need 8 to 10 hours and adults need 7 to 9 hours. Listen to your own needs!
    • Reduce sleep interruptions to preserve your sleep quality. For example, at night turn off all electronic devices and do not answer messages while you sleep.

    3. Respect your biological clock

    This particularly concerns adults who are either early birds or night owls. Another example are teens who have a biological tendency to go to bed later and sleep in later as compared to adults.

    4. Adopt a healthy sleep hygiene

    Practice sleep hygiene that takes into account the two other pillars of health, nutrition and exercise. For example, drink enough liquids during the day, but avoid large amounts of fluid in the evening, don’t eat a heavy meal before going to bed, and minimize your caffeine and alcohol consumption, especially in the evening. Physical exercise should always be part of your life, but practicing a physical activity too close to bedtime can delay falling asleep.

    5. Create a sleep routine

    The stress experienced during the day can have an impact on your night’s sleep. By creating a relaxing and consistent routine before going to bed, you will reduce stress and send the message that it’s time for sleep! Your routine should not include time spent on screens, which sends an awake signal to your brain and delays melatonin secretion.

    6. Create a safe and comfortable environment

    Your bedroom should be a room devoted to sleep and intimacy only. Choose a cool indoor temperature, comfortable bedding and try to reduce the ambient sound level and exposure to light during the night.

    See also sections on sleep needs at different ages:
    “Sleep: a personal and lifelong natural need” and “age-specific dos and don’ts”

    * SLEEPINESS VERSUS FEELING FATIGUE
    Sleepiness is the urge or need, difficult to repress, to sleep during the day. Not to be confused with fatigue, which is a feeling of exhaustion that requires one to rest, but that does not translate into involuntary sleep or an excessive need for it. Tired people can fight sleep without difficulty during the day. Sleepy people, on the other hand, are consumed by sleep. They can fall asleep easily in class, at work or while driving, for example. Sleepiness is not a normal state because it is related to either an acute (sleep deprivation) or chronic sleep loss or poor sleep quality. Severe sleepiness is often a critical symptom of sleep disorders, but also of certain medical or psychological problems. Don’t sleep on it!