A 2017 study looked into the short and long-term health consequences of sleep disruption.
Researchers noted that sleep has links to several brain functions, including:
- Memory: Sleep disruption may affect memory processing and formation.
- Performance: People’s performance at work, school, and other settings is affected by sleep disruption. This includes focus, emotional reactivity, decision-making, risk-taking behavior, and judgment.
- Cognition: By affecting stress hormones, sleep disruption may affect cognition.
2. Lower weight gain risk
The link between weight gain and obesity and short sleep patterns is unclear.
There have been several studies throughout the years that have linked obesity and poor sleep patterns.
A 2018 study suggests that people who regularly sleep less than seven hours a night are more likely to have a higher body mass index (BMI) and develop obesity than those who sleep more.
Researchers suggested sleep deprivation is associated with higher levels of gherlin (the hunger hormone), salt retention and inflammatory markers. They also noted that decreased sleep results in increased fatigue, which may affect a person’s desire or ability to exercise and maintain a healthful lifestyle.
More research is needed to better understand the links between poor sleep and weight gain.
3. Better calorie regulation
Similarly to gaining weight, there is evidence to suggest that getting a good night’s sleep can help a person’s body take in fewer calories.
For example, a 2022 clinical trial found that overweight adults who increased their sleep duration took in fewer calories compared with a control group.
The adults increased their sleep by 1.2 hours on average and took in around 270 calories fewer than the control group. The researchers suggested that improving and maintaining healthy sleep duration could help with weight loss and obesity prevention.
4. Greater athletic performance
Adults need between 7 and 9 hours of sleep a night, but recent studies have suggested that athletes may need more.
Sleep is important for athletes and people participating in sports because the body heals during sleep. Other benefits include:
- better endurance
- more energy
- better accuracy and reaction time
- faster speed
- better mental functioning
5. Lower risk of heart disease
One risk factor for heart disease is high blood pressure. According to the Centers for Disease Control and Prevention (CDC)Trusted Source, getting adequate rest each night allows the body’s blood pressure to regulate itself.
Getting a good night’s sleep can also reduce the chances of sleep-related conditions such as apnea and promote better overall heart health.
6. More emotional and social intelligence
Sleep has links to people’s emotional and social intelligence. Someone who does not get adequate sleep is more likely to have issues with recognizing other people’s emotions and expressions.
For example, a 2022 study looked into the relationship between sleep quality and duration and emotional intelligence.
477 participants were asked to complete questionnaires about sleep habits and emotional intelligence. People who routinely experienced higher quality sleep tended to perceive themselves as having better emotional intelligence, such as doing well in social interactions, maintaining relationships, feeling positive and controlling impulses.
7. Preventing depression
The association between sleep and mental health has been the subject of research for a long time. A 2016 meta-analysis concluded that insomnia is significantly associated with an increased risk of depression.
The review suggests that sleep loss may result in cognitive alterations that lead to depression risk.
Sleep disturbance may also impair emotional regulation and stability, as well as alter neural processes, which may all lead to symptoms of depression.
8. Lower inflammation
There is a link between getting adequate sleep and reducing inflammation in the body.
For example, a 2019 study found a significant positive association between greater sleep inconsistency and higher levels of inflammation, particularly in women.
The study suggested that inconsistent sleep, where a person goes to bed at inconsistent times or wakes up at different times each night, can disturb the body’s process of regulating inflammation during sleep.
9. Stronger immune system
Sleep helps the body repair, regenerate, and recover. The immune system is no exception to this relationship. Some research suggests that deep sleep is necessary for the body to repair itself and strengthen the immune system.
However, scientists still need to do further research into the exact mechanisms of sleepregardards to its impact on the body’s immune system.
Stages of sleep
When people sleep, their body goes through four stages of sleep.
Three of these stages are non-rapid eye movement (NREM) sleep, with each stage a progressively deeper sleep. The final stage is rapid eye movement (REM) sleep, where dreaming mostly occurs.
The body cycles through each stage around four to six times over the course of a night.
Read on to find out more about each stage of sleep.
Stage 1 NREM (Light sleep)
This is the lightest stage of NREM sleep, where a person transitions from wakefulness to sleep.
In this stage, a person’s brain waves, heartbeat, breathing, and eye movements slow. Their muscles also relax, with occasional twitching.
A person usually spends only 5% of their total sleep time in stage 1, which typically lasts several minutes at a time.
Stage 2 NREM (Deeper sleep)
In this stage, a person’s heart rate slows and muscles relax further. Their body temperature drops and eye movements stop.
A person’s brain-wave activity slows but they experience brief bursts of electrical activity, known as sleep spindles. Studies suggest sleep spindles help with memory consolidation.
People spend most of their total sleep time in stage 2 (about 45%). This stage typically lasts around 25 minutes in the first cycle, with time increasing in each cycle.
Stage 3 NREM (Deepest sleep)
This is the deepest stage of sleep, also known as slow-wave sleep (SWS), and accounts for about 25% of total sleep time.
A person’s heart rate, breathing, and brain waves slow to their lowest levels, and muscles completely relax. This stage is the hardest to awaken from, and when sleepwalking, bedwetting, and night terrors occur.
In this stage, a person’s body repairs itself, regrows tissues, strengthens the immune system, and builds bone and muscle. A person needs this stage of sleep to wake up feeling refreshed.
Stage 4 REM (Dreaming)
This is the stage of sleep where dreaming and nightmares mostly occur. It usually begins about 90 minutes after a person falls asleep.
A person’s eyes move rapidly from side to side with eyelids closed during this stage, and heart rate and breathing increase.
Brain activity becomes closer to that seen in wakefulness, but arm and leg muscles become paralyzed to stop a person from acting out their dreams. Experts believe a person needs some REM and non-REM sleep for memory consolidation.
People spend around 25% of total sleep time in REM sleep, with each cycle lasting from 10 minutes to an hour.
How much sleep do we need?
Sleep needs vary from person to person, depending on their age. As a person ages, they typically require less sleep to function properly.
According to the CDC, the breakdown is as follows:
- Newborns (0–3 months): 14–17 hours
- Infants (4–12 months): 12–16 hours
- Toddler (1–2 years): 11–14 hours
- Preschool (3–5 years): 10–13 hours
- School age (6–12 years): 9–12 hours
- Teen (13–18 years): 8–10 hours
- Adult (18–60 years): 7-plus hours
- Adult (61–64 years): 7–9 hours
- Adult (65+ years): 7–8 hours
As well as the number of hours, the quality of sleep is also important. Signs of poor sleep quality include:
- Waking in the middle of the night.
- Still not feeling rested after an adequate number of hours of sleep.
Tips for improving sleep
Some things a person can do to improve sleep quality are:
- Avoid sleeping in when you have had enough sleep.
- Going to bed around the same time each night.
- Spending more time outside and being more active during the day.
- Reducing stress through exercise, therapy, or other means.
Sleep is a vital, often neglected, component of every person’s overall health and well-being. Sleep is important because it enables the body to repair and be fit and ready for another day.
Getting adequate rest may also help prevent excess weight gain, heart disease, and increased illness duration.