I have always been quite happy with six hours sleep and little more. I also can operate for extended periods on four hours but that is still not sustainable without a recovery sleep after several days at most. This turns out to be the experience of plausibly one percent of the population.
It also turns out that much more than eight hours is ill advised as well. So we can presume that the standard does have a reliable biological basis. It is just that we really have not become precise at all about all this.
Everything else about sleep we already know from our own experience.
How Much Sleep Do You Need (The Answer May Surprise You)
When asked ‘how many hours of sleep do I need?’ most people will answer ‘eight hours’, without knowing why or where that number comes from. Yet many people are surviving on more or less sleep than this. Have you ever challenged the assumption that you need eight hours to function?
In this article, we’ll examine exactly how much sleep you should be getting and why. We’ll also talk about whether it’s possible to be healthy if you miss out on sleep and whether you can sleep too much.
Here is how much sleep people of different ages need, according to the National Sleep Foundation:
- Newborns: 14-17 hours
- Infants: 12-15 hours
- Toddlers: 11-14 hours
- Preschoolers: 10-13 hours
- Schoolchildren: 9-11 hours
- Teenagers: 8-10 hours
- Adults up to 64 years: 7-9 hours
- Adults over 65 years: 7-8 hours
Why We Need to SleepIt’s important to understand exactly why we need sleep; after all, we spend a third of our lives unconscious. So there has to be a good reason for it! We imagine that our brain shuts down to allow us to be unconscious, but this isn’t the case. It’s still very active throughout the night.
We’ve come to understand a lot about what happens during sleep, through sleep deprivation studies. By measuring the negative effects of sleep deprivation, scientists have come to understand what the brain and body are doing while we slumber. While there is no definitive conclusion, experts generally agree that this is what happens when we get proper rest:
- Processing memories. Everything that we learn and do throughout the day ends up in our short-term memory. While we sleep, we give the brain a chance to process these experiences and store them in our long-term memory. Moving information from short to long-term memory strengthens it so that we will be able to recall it later.
- Dealing with emotions and feelings. Some scientists believe that REM sleep is the time in which we process difficult experiences. Through purging our memories of unwanted information, experts agree that we use this time to understand unpleasant situations.
- Healing and repair. This Harvard article outlines the importance of the restorative function during sleep. The article explains that sleep deprivation leads to a weakened immune system and eventually, death. One study examined how the brain uses sleep to remove neurotoxic waste which accumulates throughout the day. This suggests that sleep is essential for our brain to be able to expel the harmful byproducts of our physical and mental activity.
- Resting. It seems obvious to mention this, but our bodies need to rest so we can build up our energy stores and tackle the next day. We can only do this by ceasing to expend energy. So while we are resting, and not using our energy stores, we can generate more energy.
- Hormone production. The hormones that we produce and regulate while we rest, show that the brain is doing important work. We conserve cortisol levels while we’re sleeping so that we can use it in the morning. Our bodies also regulate the release of hormones associated with hunger, meaning that a lack of sleep can lead to feeling hungry.
Do You Need Eight Hours?So how much sleep do you actually need? Are those eight hours cutting it or could you survive on less? In short, there is no one size fits all answer. It depends on several factors such as age, gender, genetics and how active you are during the day.
AgeThis graphic from The National Sleep Foundation gives an overview of how much sleep do you need at each age. According to the chart, adults (aged between 26 and 64 years) should be getting no more than 10 and no less than 6 hours each night. The graphic also shows that the correct amount of sleep for young adults is 7-9 hours. For teens and elders, 8 hours also falls within the recommended range. Most experts agree with these guidelines, so it’s likely that this is where that all-encompassing eight hours comes from. Babies and children need more sleep, but we discuss them less because they usually have no trouble dropping off. Troubles with sleep usually come to prominence in early adulthood and remain throughout our lives.
As for how the experts got to those numbers, there are a few different methods. One method was the analysis of data from hundreds of sleep studies to find the averages.
Popular Science argues that eight hours are far from arbitrary and that, given the chance, our bodies will always get this much sleep.In two experiments, participants had no indications about the time of day, remaining in the dark with no access to clocks. In both instances, the majority of participants would still sleep for eight hours; no more, no less.
GenderSo that’s how much sleep do you need according to your age, but what about gender?
Everyday Health posits that there are nuances between the quality of sleep that men and women are able to get.The article doesn’t suggest any hard and fast rules but focuses on the factors that can interrupt us at bedtime. For example, pregnant women may need to get more than the recommended range as they experience a huge toll on their energy. Whereas men can be more prone to sleep disorders, needing more hours of sleep to compensate.
GeneticsGenetics can play a part in how much sleep you’re likely to need. If you have inherited qualities that lead to sleep disorders, such as sleep apnea, it’s important to sleep longer to make up for your poor quality sleep. People who are active during the day do more damage to their muscles which takes longer to recover.
Effects of Sleep DeprivationWhile we sleep, our brain goes through different stages; REM (Rapid Eye Movement) and NREM (Non-Rapid Eye Movement). Further to that, NREM sleep is also characterized by three distinct stages. Both REM and NREM cycles alternate throughout the night, lasting a varying amount of time.
- REM: this is the stage at which dreams occur. The body is temporarily paralyzed so that we can’t injure ourselves by acting out our dreams. The brain is much more active in this state, supporting the theory that we use this time to process memories and deal with emotions.
- NREM: throughout the three stages of this cycle, our bodies prepare for deep sleep and then drop into it. Once in a deep sleep, the body can repair muscle, tissue, bone strength and the immune system. Until 2007 NERM was broken into four steps. Steps three and four were uultimately combined.
So it stands to reason that interrupting these essential sleep stages can be harmful. But it’s quite surprising just how risky it can be. This is a general overview of the effects sleep deprivation has on your mental and physical state:
- Tiredness, exhaustion and lack of motivation.
- Contributes to the development of depression.
- Contributes to the onset of Alzheimer’s.
- Weakened immune system, leading to the inability to fight off bacteria and viruses.
- Reduced brain function and motor skills.
- Hallucinations and delusions.
- Obesity; from a constant feeling of hunger and lack of energy to exercise.
- Serious health risks such as heart disease, some cancers, stroke and diabetes.
Can You Train Yourself to Need Less Sleep?It is not advisable to get less than the recommended amount of sleep. Yet, data from American Sleep Association, shows that 35.3% of adults sleep for less than 7 hours per night. This number rises to 40% reporting a short sleep duration after the age of 40.
According to this BBC article, there are people who can thrive on 6 hours or less per night, doing no damage to their health.However, they are referred to as an “elite” and believed to represent only 1-3% of the population.
Sleep expert, Jim Horne, suggests that it is possible for people to get good quality sleep, even in a 6 hour period. He conducted a study where participants reduced their sleep duration over time and still managed to function throughout the day. But even he doesn’t advocate for intentionally sleeping in short bursts.
Rather than training ourselves to need less shut-eye, we can relax if we don’t get the recommended amount of hours every night. After all, trying to force yourself to sleep and worrying about not sleeping are stressful. It becomes a vicious circle; you’re stressed about not sleeping, so you can’t get to sleep, then you worry about the impact of that lack of sleep.
Can You Get Too Much Sleep?The previously mentioned BBC article suggests that you can ‘bank’ sleep. This is the act of sleeping more than eight hours in anticipation of not getting a full night at some point. Yet, Sleep Health Foundation disagrees, saying that you cannot ‘bank’ sleep. They also state that when you suffer sleep deprivation, you will build up a ‘sleep debt’ which you need to ‘pay’ back. Meaning that, when you can, you will sleep more to make up for it.
With all this talk of ‘banking sleep’ and ‘sleep debts’ you might ask whether it’s a good idea to try and build up more hours when you have the chance.
Evidence suggests that this isn’t a great idea either.
A 2011 study found that people who slept for around 300 minutes per night had a higher survival rate than those who slept more than 390 minutes.It’s worth noting that the data showed sleeping for less than 300 minutes produces the lowest survival rate.
Controversially, Dr Christopher Winter argues that we don’t all need the recommended amount of sleep. Instead, we should get what we need. He explains that you can sleep too much and that your body will let you know if it’s getting too much rest. This includes waking before your alarm, waking throughout the night and taking a long time to fall asleep.
Some sources even say that too much sleep can lead to the same health concerns as sleep deprivation. According to WebMD, you can count diabetes, heart disease, depression and a high mortality rate, among the risks of sleeping more than 9 hours every night.
How to Get Good Quality RestSo you shouldn’t get too much sleep and you shouldn’t get too little. It’s not easy to know exactly how much you do need. However, with a stress-free bedtime routine, you will soon begin to get the best amount of hours for you. When you can drop off and wake up without any hassle, that will be the amount of sleep you actually need. In fact, Sleep.org suggests sleeping without an alarm for a week to let your body find its rhythm naturally.
One thing is certain; getting the best quality sleep beats getting a lot of poor quality sleep. In this article, we outline ten steps you can take to ensure that you get the best night’s sleep. These tips address what might stop you from dropping off and will help to reduce any factors that might disrupt you once you’re asleep. Having a regular, healthy sleep routine will be sure to help you get to sleep.
But to stay asleep, you need to address the interferences that may wake you throughout the night.
We talk about how it’s essential to have a relaxing environment so that you can drop off with ease. But this is also important so that you’re not woken up through the night. For example, it’s difficult to fall asleep in noisy surroundings and to stay asleep when you’re still exposed to noise disruption. Likewise for having comfortable bedding and a cool environment. If you are shifting around a lot and overheat, your brain will wake you up to take care of the problem.
Waking several times throughout the night is detrimental to quality rest, even if you sleep a lot to make up for it. The brain needs to work through the stages of sleep and if it can’t do that uninterrupted, you will miss out on essential healing and repair.
So it seems like that eight-hour figure could be the golden number after all. At least as a starting point. Sleep much more, or less, than this and you could find yourself with a host of health problems. Of course, that number only applies to young to middle-aged adults. It should be adapted depending on your gender, genetics and activity levels. It would be sensible to aim to get the recommended amount of sleep, but even more important not to become stressed out trying to do it. Try to get eight hours, but don’t worry if you can’t get that every night.
FAQHow much sleep do you need to build muscle?
Poor sleep quality can result in reduced muscle mass. In one study it was found that men having more than eight hours of sleep had better muscle mass than that who had six or seven. For this reason, it is advised to get at least eight hours of sleep.
How much sleep do you need when sick or have a cold?
The common cold can make it hard to fall asleep or stay asleep through the whole night. We know that not getting enough sleep is bad for your immune system. For this reason, it’s recommended to get a few hours more sleep than you normally get while you are sick. Review the chart at the top of this article with sleeep demands by age. Try to hit the minium if not the maximum while sick.
How much sleep do you need after surgery?
Sleeping after a surgery can be difficult. Most patients return to their normal sleep cycle after a week. A recent study has found that sleep-promotion therapy may be helpful. It is smart to get as much sleep as your body feels like it needs after a surgery. Often this may be more than normal as your body heals.
Have a question we didn’t answer? Ask it in the comments below and we will add it to the FAQ section.