Sleeping is an essential part of our lifestyle. It helps the body to restore and strengthen itself, making us feel recharged when we wake up. This makes it as important as exercise and a balanced diet.1 But knowing its crucial role for our wellness, why do most of us still don’t get the right amount of sleep? And how exactly does a good sleep be beneficial to your health?

Why Do We Sleep?

Sleep is a pillar of a healthy lifestyle and there are two main reasons why we experience it. First, it is our body’s natural way of restoring itself. Sleeping at night boosts the growth hormone production to repair damaged cells and tissues, maintain body structure, aid metabolism, and regulate blood sugar levels.²

Secondly, it promotes brain health. When we sleep, the nervous system gets rid of the toxins from the brain, reducing risks of mental-related illnesses such as Alzheimer’s disease. This is also the time that your brain processes the information you have collected during the day to become memories.³

Aside from these two major reasons, experts also relate sleeping to these theories to further explore the science behind it:⁴

• Inactivity theory – it is also known as the adaptive or evolutionary theory. This suggests that sleeping at night is an animal’s way of survival to keep them from harm during this vulnerable time of the day. Animals that can keep inactive at night are less likely to fall prey to predators, compared to those who remain awake.
• Energy conservation theory – this states that the main purpose of sleeping is to lessen the energy demand of the body for specific times of the day or night, and when hunting for food is least efficient. The energy conservation effect appears to be true as the metabolic rate decreases up to 10% when we sleep.
• Restorative theory – this tells that sleeping is the body’s way of repairing and regenerating the depleted cells to aid biological functions. Several findings support this by stating that sleeping is beneficial for muscle repair, tissue growth, protein synthesis, and hormone production.
• Brain Plasticity theory – this states that sleep is an important part of brain development and function. This serves as the primary reason why infants and children sleep an average of 14 hours a day. This is also seen relevant to adults as sleep deprivation affects how they learn and how they perform tasks.

Stages of Sleep

Sleeping is more than just a resting phase for your body. It’s also an active process that follows a pattern regulated by circadian rhythm or body clock, a natural mechanism responsible for your sleep-wake cycle.5 And when you go to bed, you will normally experience two types of sleep: the non-REM sleep or the quiet sleep, and the REM sleep or the paradoxical sleep. More specifically, you will undergo these stages:⁶

• Entering sleep – during this phase, you are still awake but your brain starts to slow down and relax. You might experience hypnagogic hallucinations, strange sensations like hearing someone calling your name or feeling that you are falling. Hypnic jerks, or sudden sleeping jolts, might also happen which is fairly normal as you enter sleep.
• Stage 1: Non-REM Sleep – this is the lightest stage of sleep where you transition from being awake to being asleep. The brain releases high amplitude theta waves, causing deep relaxation and will eventually put you to sleep. This happens around 5 to 10 minutes
• Stage 2: Non-REM Sleep – the brain starts to produce sleep spindles, or rapid and rhythmic brain wave activity, and makes you less aware of your surroundings. Your heart rate also starts to slow down and your body temperature starts to decrease. This stage normally lasts up to 20 minutes.
• Stage 3: Non-REM Sleep – this is also known as the delta sleep. This is the stage where delta waves are produced by the brain to deepen sleep. As you transition to a deeper sleep, you become less responsive to the disturbances around you. This is also the time that the body produces growth hormones to nourish and repair the bones and muscles.⁵ Bed-wetting is most likely to happen during this stage, but might also occur during other stages. Sleepwalking is more often to occur during this stage.
• REM Sleep – this is the deepest stage of sleep and where most of the dreaming occurs. Eye movements, increased brain activity, and faster breathing normally characterizes it. This is also called paradoxical sleep as muscles tend to be relaxed while the brain and other body systems become more active. Body chemicals are also released to cause temporary paralysis to the body so that we don’t act out our dreams.⁵

In terms of the sequence of these stages, they don’t go as linear as they might seem. Sleep starts at stage 1, progresses to stage 2, transitions to stage 3, and loops back to stage 2 before entering REM sleep, then goes back to stage 2. These sleep stages cycle around for about 4 to 5 times when you sleep at night.⁶

Benefits of a Good Sleep

There are a lot of factors as to how you can tell if you have slept well or not. But one thing that contributes to a good sleep is the production of melatonin, which can only happen at night or in the dark. It is a natural hormone that promotes the quality of sleep. Once you sleep soundly regularly, you can experience these benefits:⁷

• Fewer calorie intake – getting enough sleep relatively decreases your appetite and sharpens your ability to resist food, making you eat less. On contrary, studies show that if you’re sleep-deprived, your brain is wired to be greatly enticed by foods that are high in fat, carbs, and calories.^8,9,10,11
• Improved mood and brain function – a good night's sleep boosts concentration, cognition, memory, and problem-solving skills. It also improves your disposition as it helps normalize your mood right after, making you less irritable or angry and enables you to cope with stress better.^{12,13,14,15,16}
• Enhanced athletic abilities – sleeping soundly relates to increased athletic performance. A study shows that it significantly improved speed, accuracy, reflexes, and mental awareness among basketball players. Meanwhile, lack of sleep in women weakens grip strength, slows down walking pace, and increases the difficulty in doing physical activities.^17,18
• Stronger immune system – adequate sleep boosts your immunity to illnesses. It improves the production of T cells to fight against virus-infected cells that cancers, HIV, herpes, and flu have.¹⁹

How Much Sleep is Necessary?

Experts suggest that to get the best quality of sleep, go to bed between 8PM to midnight to give the body an ample amount of time to recharge. In terms of how many hours should you sleep, 7 to 8 hours is enough, but this still depends on your age.²⁰ Here’s a quick guide on how long each age group should sleep in a day:²¹

• Newborns (0-3 months) - 14 to 17 hours
• Infants (4-11 months) - 12 to 15 hours
• Toddlers (1-2 years old) - 11 to 14 hours
• Preschoolers (3-5 years old) - 10 to 13 hours
• School-age children (6-13 years old) - 9 to 11 hours
• Teens (14 to 17 years old) - 8 to 10 hours
• Young adults (18-25 years old) - 7 to 9 hours
• Adults (26-64 years old) - still 7 to 9 hours
• Older adults (65 and above) - 7 to 8 hours

You can also observe the decreasing trend in the required hours of sleep as a person ages. This is because growth hormones generate faster and more effectively while we sleep, that’s why longer hours are required for younger people to facilitate its production. However, sleeping hours for those who are tired, sick, or stressed might be necessarily longer to help recovery.²²

Effects of Sleep Deprivation

Sleep deprivation is simply the lack of sleep. This drains out your brain stability and puts your physical health at risk. You can tell someone is sleep-deprived if he/she looks very tired, irritable, have mood swings, has difficulty in focusing or remembering things, and has low sex drive.²³

However, this can be caused by sleeping disorders like insomnia or apnea; changes in sleeping pattern because of old age; existing health issues like heart problems, cancer, or depression; or even stress.²⁴ And once you’re sleep-deprived, your body is exposed to these various negative effects:

• Obesity - lack of sleep is the biggest risk factor for obesity by altering hormones that are related to eating. It reduces leptin, making it ineffective to suppress your appetite; and increases ghrelin, making you feel more hungry.25 It also affects brain functions to control food intake. Your brain becomes more wired to be enticed by food high in carbs, fats, and calories.26 To make things worse, it may reduce your resting metabolic rate and might reduce your muscle mass.^27,28
• Hormonal imbalance - aside from altering leptin and ghrelin levels, sleep deprivation also affects other important hormones. It makes insulin react abnormally to sugar; it blunts thyroid hormone to manage fatigue and metabolism; it raises cortisol level that makes sleeping even more difficult; it reduces the production of sex hormones for both men and women that leads to poor sex drive.²⁹
• Chronic Diseases - sleep deprivation increases your risks for chronic diseases. This includes diabetes, heart disease, and high blood pressure. This also affects mental health by increasing risks for depression, anxiety, and bipolar disorder.³⁰
• Poor mental performance - along with mental illnesses, the lack of sleep also affects mental performance. It disrupts the prefrontal cortex and amygdala that are responsible for sound reasoning and emotion. It also interrupts with learning and remembering.³¹
• Premature aging or death - in terms of its effects on beauty, sleep deprivation decreases moisture and pH levels in your skin, making it look dull, dry, and aged. This also causes your hair to grow thinner and make dark circles below your eyes appear.32 Also, it doesn’t just make you look older, it may as well contribute to the risk of premature death. A study shows that people who sleep less than 6 hours at night are 12% more likely to die prematurely compared to those who sleep 8 hours or more.³³

As you can observe, sleep deprivation can be caused by existing health issues to create more health issues. If you are having a hard time falling asleep, make sure to seek your doctor’s advice to help you sleep soundly before it gets worse and trigger further disorders or conditions.

How Can You Sleep Better at Night?

Now that it’s clear how sleep is beneficial to your body, it’s now time to know how you can sleep soundly. Here are a few ways that you can do to help you sleep better at night:^34,35,36,37

• Avoid heavy exercises in the evening - doing exercises above aerobic workouts might affect your sleep. This elevates your body temperature and adrenaline level, making it hard for you to fall asleep. Winding down physical activities 1 to 2 hours before sleep will help.
• Get enough vitamin D - this could help lessen the inflammation of nasal passages and the tonsils to promote smooth breathing while asleep. This can also address snoring.
• Secure room temperature - sleeping in an enclosed, warm room might not help you to fall asleep. Setting your thermostat to your desired temperature will greatly help.
• Keep it dark - melatonin promotes good sleep and is only produced in the dark. Fall asleep faster by using black curtains in your bedroom to block the light to push through. Also avoid using your gadgets that emit blue light like your phone, laptop, or TV, while trying to get some sleep. This wakes you up by abrupting melatonin production.
• Don’t eat before bed - eating too soon before sleeping triggers some changes in your blood sugar and insulin that affect your energy level. Once the sugar level drops, cortisol will help to regulate it and switch your body to fight-or-flight mode, thus waking you up. Avoid drinking alcohol or marijuana to aid sleep - alcohol and marijuana are actually sedatives and will not promote sleep. They will just turn off your brain’s cortex and put you under sedation, not total sleep. These disrupt the flow of your sleep and cause awakening several times. These also hinder you to reach REM sleep.
• Follow a consistent schedule - keeping a sleep-wake routine consistently recalibrates your body clock. This way, your body’s natural rhythm will help you fall asleep when it is really time for bed. Also, establishing habits before sleeping helps you to fall asleep faster. You can read a book, meditate, or anything that relaxes you.

Conclusion

A good sleep plays a vital role in your well-being. More than just restoring your energy, it comes with other promising effects to your body to promote good health and prevent illnesses. Just follow the necessary amount of sleep for your age and incorporate our tips to a good sleep to your routine and you’re set to maximizing its benefits to your health.