Do You Really Need 7-8 Hours of Sleep Every Night?

The answer depends on your age. We’ll share all the details along with 10 top health benefits of adequate sleep.

Last updated: May 15th, 2022
Sleep Guide

Have you ever stayed up all night studying for an exam or worked late hours to meet an early morning deadline? If yes, you have probably noticed how drained your entire body felt the following day due to the lack of energy stemming from getting little-to-no sleep. Sleep is an essential part of our lives that allows our bodies to rest, recharge, and be refreshed for the next day. Without enough sleep, our bodies and brains cannot function properly, which is why we can experience a "crash." Getting adequate sleep not only helps our bodies physically recover from exerting energy throughout the day, but it also helps refresh our cerebral and cognitive functions.

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Why do we need sleep?

Sleep is an essential function that allows our bodies to get the rest it needs after working hard all day. A healthy amount of sleep is vital for neuroplasticity, which is the brain’s ability to change its activity in response to experiences over the course of our lives by reorganizing its structure and functions.

When we don’t get enough sleep, we are more likely to run into health risks such as worsening symptoms for depression, high blood pressure, migraines, and seizures. Immunity is also compromised, increasing the likelihood of infections and illnesses.

Studies show that restricting sleep to four hours per night for six days, followed by sleep for 12 hours per night for seven days, resulted in at least a 50% decrease in production of antibodies to the influenza vaccination in comparison with subjects who had regular, consistent sleep hours. Good quality sleep can bolster the T cells (a type of white blood cell that fights off infections) by enhancing the ability of these cells to adhere to and destroy viruses or other pathogens.

Additionally, sleep plays a role in metabolism where even one night of missed sleep can increase the risk of diabetes in an otherwise healthy person. There are many crucial connections between sleep and your health, which is why it is highly recommended to maintain a decent sleep schedule.

Sleep’s impact on academic performance

The human brain is not wired to absorb vast amounts of information on zero sleep and be expected to retain it for an exam. Although it is inevitable that students may sometimes need to cram the night before a test or final, especially with all of the other events going on during their college life, it is recommended to at least clock in a couple hours of sleep in order to avoid the full negative effects of staying up.

If we don’t get enough sleep, we are unable to process and retain the information we have learned during the day. This is especially important for college and high school students who are notorious for staying up all night doing homework or studying for exams. In fact, many college students consider “all-nighters” a part of the college experience and have pulled at least a few during their time in school. However, staying up all night to study can adversely affect both your health and academic performance. It’s important to study as much as you can, but not at the cost of your sleep.

According to researchers at Texas A&M University, all-nighters rely on short-term memory, and the information you learn or study during this time will likely not be retained at all for the exam. With each hour of sleep deprivation, your brain loses efficiency and experiences a sharp decrease in memory and cognitive abilities. It is recommended by the researchers to study in small increments well in advance of a test or final to have the best chances of achieving a good score. However, if you must cram the night before, they recommend studying as much as you can until bedtime and then waking up early in the morning to review the material again. That way, getting those extra hours of sleep will rejuvenate your mind and body, better preparing you for the exam.

How many hours of sleep should we get?

The amount of sleep we need depends on our age. The younger you are, the more sleep you will likely require. Adults generally only need seven or eight hours of good-quality sleep on a regular schedule. Here is a quick breakdown of sleep recommendations, according to the CDC and the American Academy of Pediatrics (AAP):

  • Newborn (0-3 months): 14-17 hours per 24 hours (including naps)
  • Infant (4-12 months): 12-16 hours per 24 hours (including naps)
  • Toddler (1-2 years): 11-14 hours per 24 hours (including naps)
  • Preschool (3-5 years): 10-13 hours per 24 hours (including naps)
  • School-aged (6-12 years): 9-12 hours per 24 hours
  • Teenager (13-18 years): 8-10 hours per 24 hours
  • Young Adult (19-25 years): 7-9 hours per night
  • Adult (26-64 years): 7-9 hours per night
  • Older Adult (65+ years): 7-8 hours per night

This is just a general, baseline recommendation. It is important to consider your own lifestyle to see how much sleep will be adequate for you. Some questions you can ask yourself are:

  • Do you have other health issues and/or are you high-risk for any disease?
  • Do you frequently exert a lot of energy (e.g. playing sports or training)?
  • Do you work a labor-intensive job?
  • Do your daily activities require high alertness (e.g. driving long hours, operating heavy machinery)?
  • Do you have a history of sleeping problems?
  • Do you work graveyard shifts? Has your internal clock adjusted properly?
  • Do you normally depend on caffeine to help you get through the day?

If you are experiencing serious issues with your sleep habits, it is important to first consult with a medical professional to get the help you need. Any underlying problems must be fixed in order to fully be able to rest, such as acknowledging and treating health conditions or conflicts with other factors in your life. That way, it will be much easier to plan and prioritize your sleep schedule.

Top 10 health benefits of good sleep

While we have established the importance of sleep and why we do it, you may be wondering what the specific benefits are. Sleep affects almost every tissue in our bodies, influencing growth and stress hormones, appetite, blood pressure, cardiovascular health, and much more. Besides leaving your body feeling restored and well-rested, getting a good night’s sleep can contribute to a myriad of health benefits.

Boosts your immunity

A full night’s sleep allows your immune cells to rest and better fight off common colds, the flu, and other illnesses that come your way. Additionally, according to the American Academy of Sleep Medicine, proper sleep can help vaccines be more effective, which is especially crucial during the time of COVID-19. It is important that we continue to get sufficient sleep for optimal immune response and protection.

Strengthens your heart

Research shows that lack of sleep can increase the risk for heart disease. When you are sleeping throughout the night, your breathing rate, blood pressure, and heart rate rise and fall, a process that is important for cardiovascular health. Poor sleep quality is linked to high blood pressure and even heart attacks. As a result, skipping out on sleep can lead to a surge in stress hormones such as cortisol, which compels your heart to respond by working harder and not getting the rest it needs to function properly.

Improves your mood

When you get a good night’s rest, you are essentially setting yourself up to have a great day. Little obstacles and annoyances, such as traffic or spilling your coffee, will likely affect you less if your mind is clear, positive, and refreshed. Alternatively, studies show that even one night of subpar sleep can make you irritable, cranky, and negative the next day. This can also leave you feeling more vulnerable and stressed out, making it harder to fall asleep the next night, ultimately trapping you in a negative, counterproductive cycle.

One way to change this is by sticking to a strict sleep schedule that will allow your system to recharge and restore itself.

Promotes hydration

Getting a sufficient amount of healthy sleep plays an important role in keeping you hydrated. A 2018 study by Penn State analyzed how sleep affects the risk of dehydration in American and Chinese adults. They discovered that adults who reported sleeping six hours had significantly more concentrated urine and were 16-59% more likely to be dehydrated compared to adults who slept for 8 hours on a regular basis. This was due to the body’s hormone that regulates hydration, called vasopressin. Vasopressin is released throughout the day but its prime time is later in the sleep cycle, so if you are shortening your sleep duration, you may miss that window where more of the hormone is produced and released. This lack of vasopressin can then cause a disruption in your body’s hydration.

Improves sex drive

Not only is quality sleep great for the heart and immune system, it also contributes to sexual health by keeping testosterone levels high. Research shows that men who sleep less than six hours on average per night have lower levels of testosterone, ultimately sinking their sex drive.

Sleeping well is also believed to prevent erection problems and ensures your body is well-rested and energetic enough for intimacy. Although more research needs to be conducted, evidence does demonstrate that quality sleep can promote a better sex life, and a healthy sex life facilitates great sleep: it’s a win-win.

Increases productivity

Staying up all night and sacrificing your sleep hours has more adverse effects than positive ones, even if you think you are accomplishing more work. A 2010 study found that out of 4,188 worker participants from the United States, those who slept less had significantly worse productivity, performance, and safety outcomes with an estimated $1,967 loss in productivity per worker due to poor sleep.

During sleep, your brain creates and maintains pathways that are essential for memory formation and retention. Not only do these processes help with problem-solving skills and critical thinking, but they also help facilitate and enhance learning abilities. Sleep has been linked to improved concentration as well as higher cognitive function, both of which can increase productivity and performance at work, school, or in your everyday life.

Enhances memory

Getting enough sleep helps your brain process and consolidate your memories from that day. In fact, some procedural memories can be strengthened throughout a night of sleep, such as motor skills like riding a bike, tying shoes, or playing an instrument. This is because sleep plays a major role in forming long-term memories like procedural memory and other long-term memories that are responsible for knowing how to do certain things. Additionally, studies have shown that the slow brain waves found in stage 3 sleep (deep NREM sleep) serve as almost a courier service of sorts, transporting memories from the hippocampus (the part of the brain that is involved with emotions, learning, and memory formation) to more permanent storage sites within the brain.

Decreases the risk of car accidents

On the road, sleep deprivation can be just as dangerous as driving under the influence of alcohol or other substances since it can slow your reaction time and reduce your ability to focus. According to a study from the AAA Foundation for Traffic Safety, people who regularly sleep six to seven hours per night are twice as likely to get into a car accident compared to those who usually sleep at least eight hours. Additionally, people who sleep less than five hours per night quadruple their chances of being involved in an accident. Be aware of yourself and others on the road, especially late at night when drivers are more likely to be tired and drowsy.

Prevents weight gain

Not only does getting a good night’s rest help with cognitive functions, but it can also keep you from adding unwanted pounds. Studies have shown that people who get less sleep tend to be heavier, eat more, and are more likely to be diabetic. Sleeplessness increases the production of the hormone ghrelin, which boosts appetite, and decreases the hormone leptin, which signals the feeling of being full. Lack of sleep may also leave you feeling more stressed and low-energy, making it difficult to fight junk food cravings in the middle of the night or throughout the next day.

Increases exercise performance

In a 2013 study by the Journal of Strength and Conditioning Research, medical researchers found that sleep deprivation reduced muscle strength and physical power the following day, especially for afternoon workouts. Lack of good sleep leaves your body feeling drained, tired, and generally fatigued, so it’s no surprise that physical activity will be harder to do when you are running on little to no energy. Quality sleep is thought of as nature’s very own workout supplement, improving hand-eye coordination, speed, muscle recovery, and reaction time.

Bottom Line

Although it may seem like skipping a few hours of sleep isn’t that big of a deal, when it comes to immune health, cognitive performance, and overall well-being, these missed hours can add up quickly. The National Sleep Foundation recommends adults indulge in a full seven or eight hours of sleep per night if they want to reap the health benefits.

If you have trouble falling asleep, there are steps to take to help combat this issue, such as keeping to a strict sleeping schedule, avoiding stimulants such as nicotine and caffeine, and staying active. Of course, some reasons for chronic insomnia stem from much deeper psychological factors such as anxiety and depression, so it’s best to consult with a medical professional if your sleeping patterns worsen. There will inevitably be times where you need to stay out late or sacrifice some of your sleep, but as long as you take care of your body and allow it to recover properly, then you are on the right track of maintaining a healthy sleep schedule.