The question of how much we need to or should sleep is one that has plagued many of us on numerous occasions. This is also an area of health and science that has been vigorously studied and explored by scientists over the past few decades.
While some people believe we need a full eight hours each night, others have hinted that much less is optimal and yet others have even warned us of the dangers of over sleeping. Our discussion would also not be complete without understanding that it isn’t only about how much we sleep, but when these hours of sleep should take place and what factors affect them.
Thus in this, part 3 of our 5 part Sleep Aware Series, I will cover some of the latest research and help you decide just how much sleep you really should to be getting for optimal health in all areas of your life as we discussed in “Part 1 – Why We Need To Sleep?” So read on, as the final answer may surprise you.
Understanding the Basal Sleep Need
When addressing the facts behind the quantity of sleep, we must first start with the right question. Asking “how much sleep should we get?” is not the same as “how much sleep do we need to get?” Yes, you heard me right, it seems like a small play on words, but when it comes to sleep, as we saw in part 1, we must get it. It is a matter of life and death, or for most of us a matter of quality of health. Therefore, throughout this article I will focus more on the “need”, rather than the “should”, as I feel it drives the point across more strongly of just how important sleep really is.
Hence to help us understand this better, through various studies scientists have developed what is known as the Basal Sleep Need (BSN). Most of us have probably heard of the BMR – the basal metabolic rate, which is how many calories our bodies need to function at rest. There is also the BSN, which is how many hours of sleep our bodies need on a regular basis for optimal performance.
At this time, it has been determined that the basal sleep need for the average healthy adult is 7 – 8 hours a night. This again means, the amount of sleep that a person needs to rejuvenate the body and feel optimally healthy, both physically and mentally to take on a new day.
Sleep Minimums and Maximums
Having therefore learned above that the average person needs to sleep 7 – 8 hours a night, let us now delve deeper into these numbers and understand how we are then impacted if we sleep less than this or more.
First off, you may be thinking that you know someone or perhaps it is you yourself that sleeps only 6 hours a night and feels great and is in perfect health. Well that could very well be true. The biggest determining factor for why some people sleep so much more or less is how hectic or stressful their lifestyle is. Hence, many people who have few obligations and are generally living a very relaxed life, can actually get by on 6 hours and feel great and be healthy. There are also those exceptions of people, who do lead stressful lives and can sleep 6 or even 5 hours and claim they feel great. However for this to really hold true, we would have to examine their energy levels throughout the day, which should be stable if this really was enough sleep and also check their hormone levels, especially cortisol. Since cortisol can keep us on an artificial high.
The truth is that many of us today are sleep deprived, and we cannot say we are fine with 6, 7 or even 8 hours of sleep sometimes. We don’t need statistics or research to tell us this, just look around! We have a nation of adults addicted to coffee and many who will flat out admit that they cannot function without it. This is obviously a huge problem where our optimal health and wellness is concerned. Masking a problem does not mean that the problem is gone, and therefore we cannot be surprised when future health problems arise. Our bodies are great at coping and trying to be resilient, but we cannot get away from the fact that the body must get a certain number of hours of sleep if we are to have average, never mind optimal health. Our dependency on coffee speaks otherwise.
Up to this point scientists have found that generally speaking, people who sleep less than 6 hours regularly not only are less healthy, but have a shorter life span. Short sleep duration has been linked to: increased risk of motor vehicle accidents, increased weight imbalances, increased risk of diabetes and heart problems, increased risk for psychiatric conditions including depression and substance abuse, decreased immune function and decreased ability to pay attention, react to signals or remember new information.
Hence for average health, we need to be getting at least our basal sleep need.
In terms of sleeping too much, surprisingly studies show that this also can backfire where our health and mortality is concerned. Some, studies have shown that people who slept more than 9 hours regularly had a slightly higher mortality rate than those who slept about 7-8 hours each night. While this finding can leave you feeling apprehensive about those delicious 9 or 10 hour sleeps you may be getting each night, do not start to panic just yet.
The reason for this is that yes, if we lived happy and relatively stress free lives than our sleep would rarely need to go past 8 hours a night, but we do not. In fact today many of us are pushing the limits of what a human body and mind can handle when it comes to tasks and stress – and none of this of the pleasant kind. Thus, researchers have also noted that today many of us actually do need about 2 hours more on top of our basal sleep need to fully recover from the lives we lead. Otherwise we go into what is called sleep debt – the accumulated sleep that is lost to poor sleep habits and other causes. Also, a healthy body will tell you when it has had enough and in fact it is very hard to oversleep, so again no need to stress over sleeping too much. Chronic oversleeping however, say more than 10 or 11 hours a night usually does indicate an underlying medical condition.
So in conclusion to this section, while there is no one size that fits all, generally speaking, yes, we should all be aiming for at least 7 – 8 hours of quality sleep a night, with up to about 10 hours based on personal lifestyles.
Even though you can easily still find conflicting scientific studies on this, the simple proof is in you. The test is to look at the number of hours you are sleeping now and see if you are feeling well rested and can function optimally each day, without any stimulating aids and with balanced energy levels throughout the day. Most adults today will unfortunately find that they do not feel rejuvenated enough based on BSN alone, due to the extra hectic and stress-filled lifestyles they lead. And while many still think it is okay to sacrifice sleep and that they cannot possibly afford to sleep that much, we cannot deny that there is a deeper issue that hides here. When we stop having “time” to sleep properly or eat properly than we should realize we have a matter that needs our serious attention. My strong advice is thus to really take a deep look at your life and reassess your health and lifestyle priorities to really get the best life quality and longevity.
When Should We Sleep to Maximize the Benefits?
Okay, so you may be thinking, “great, now I know how much I really need to sleep, so I can do it any time I have the time.”
Well it is not that simple.
Some of the most valuable sleep takes places before midnight. This is due for a few major reasons. First, melatonin is most active between 9pm and 9am. This hormone is super sensitive to daylight and will only be secreted from the pineal gland during the natural dark hours of the 24 hour cycle, also it is heavily influenced by how bright our environment is prior to falling asleep or waking up. This is important to realize as some people may say, that they will party all night and sleep all day. Well, while you may still fall asleep during the day, if for no other reason than pure exhaustion, you will not be getting the same quality of sleep as if you slept those hours between 9pm and 9am.
The second very important reason for making sure we are asleep by 11pm is that during roughly the hours of 11pm and 1am is when the most critical recharging of our adrenals and gallbladder takes place. While the gallbladder may not seem that important to some, the adrenals are critical to good health. Adrenal fatigue is a condition that is becoming more and more prominent today for no other reason than too much stress and not enough sleep.
Another reason to sleep at a particular time, is that growth hormone levels peak during the first part of the nocturnal sleep and are highest during each stage 3 and 4 of sleep (as explained in part 2 of the series). This hormone is critical not just for growth in kids, but in proper cell regeneration in adults and thus there is no coincidence that people who regularly sleep well age less drastically.
Thus for the typical person who starts work at 8 or 9am, I recommend getting into a daily routine of 10pm – 6am sleep (give or take an hour). This makes sure that not only are you sleeping the minimum hours needed, but also at the most efficient time to get the best quality sleep you can.
Age, Sex, and Other Variations
It is no surprise that children, especially babies need more sleep than adults. Remember, from part 1 that during sleep we are doing the majority of our growth and regeneration. Hence as babies and children are in the highest growth and development stage, they need much more sleep than adults.
Typically babies need the most sleep, then young children or teens. Babies start off sleeping as much as 18 out of the 24 hours of the day, and decrease this number variably as they continue to grow. By the time kids are teens they typically need about 9-10 hours of sleep per night, or about 2 hours more than adults. Most teens however, do not come close to getting this type of sleep quality and hence suffer often in both their health, behavior and academics. When teens do sleep for what seems like “too long” it is usually done not at optimal times for the sleep to be most effective and at the same time, gets grossly prolonged as many of their bodies are suffering from sleep debt and hence trying to make up sleep say on weekends or vacation times.
Now having said that many people continue to apply this and think that the elderly therefore need less sleep than adults. This however is not quite true. It may only seem that older people need less sleep because their lifestyles are usually much lower in terms of stress, and some have many debilitating health problems which prevent them from proper sleep. However overall, seniors need just as much sleep (in terms of the basal sleep need) as adults do. See the following table for a general breakdown.
*Chart courtesy of the National Sleep Foundation
When it comes to the sexes, women actually need more sleep than men. This is due primarily to the lifestyles they lead and structures of their brain. Even something like caring for children that can be done by both a mom and a dad, is going to take more effort and energy out of a woman than a man, and hence the woman actually needs more sleep to regenerate as well as a man. Now having said that, who actually gets more sleep is usually not who should be getting more sleep in most families, as women do tend to take on too many family responsibilities.
In terms of other variations, one should also note that we need to sleep more whenever we are sick, no matter how big or small the sickness may be. It is therefore not an exaggeration in any way, when we are told to rest when we are sick. Literally we should be sleeping. Remember, it is then that your body can put most of its focus and attention on healing and thus get you back to your perfect health sooner.
Finally, the biggest variation, which accounts for the main reason why there is no magic or set number for us out there when it comes to amount of sleep is stress. The more stressful a person’s life is, the more they need to sleep. We know thanks to medical science up to this point that first and foremost, stress elevates our cortisol hormone. This actually serves as a double negative. First, chronically elevated cortisol levels lead to many biochemical imbalances within the body, which can lead to various health issues, also which the body has to work hard to repair. And if this wasn’t bad enough, chronically elevated cortisol levels actually make it hard to fall asleep – hence you cannot do the very thing that you need most of. Therefore it is very important to realize this, accept it and do something about it, such as serious lifestyle changes. That is of course if your health matters a lot to you.
So while there is no one magic number for how much we need to sleep and it ends up being a very personal matter, values typically range between 6 and 10 hours, with 7-8 hours being the optimal minimum.
Ultimately remember that as your life changes, your sleep patterns will change and your best bet to know how much sleep you really need is to see how you feel each day. The right quality and quantity of sleep leaves us feeling well-rested, refreshed, rejuvenated, with clear and sharp mental functions and balanced energy levels throughout the day and with no need for any kind of stimulants.
If you are not getting enough sleep, and you genuinely care about your health, than I encourage you to do a serious reflection on how you are living your life and how you can re-prioritize things in order that you get the best health and happiness out of it possible!
So while some of us may know that we need to sleep more, falling asleep and staying asleep may be a whole other story. Hence I invite you to join me in part 4, where we explore things that hurt and help our quality of sleep.
Till then sleep well!
Resources & Other Helpful Sites
For more help and information on sleep check out the following sites: