We often think of sleep as a period in which the mind and body is totally at rest, but in fact the very opposite is true. When you sleep, your body is working incredibly hard.
During your waking hours, you take in an enormous amount of data, both in what you experience and how you feel emotionally, and sleep is when the brain processes this data into memories.
Our bodies also use sleep to carry out essential maintenance and housekeeping roles, for example repairing the daily wear to our joints and muscles and ridding the body of waste products that have built up over the day.
Sleep is therefore absolutely essential for your physical and mental wellbeing. When you get enough sleep, you wake feeling refreshed and ready to tackle the day and when you don’t get enough your alertness, mood and productivity suffer.
The amount of sleep per night that an individual requires in order to be able to function optimally, without feeling sleepy, is their sleep need.
If you don’t think that you’re getting enough sleep, Sleepstation can help. Our highly-skilled team will work with you to identify the factors affecting your sleep and we can provide support and guidance to make sure you get the right amount of sleep for you.
Your individual sleep need is regulated by the interplay of two important biological elements: your circadian rhythm and sleep homeostat. The circadian rhythm is the body’s internal clock. It cycles roughly every 24 hours (generally slightly longer for men, slightly shorter for women) and is responsible for making you feel drowsy or alert.
The main external stimulus for your body clock is sunlight. It only takes a few minutes of sunlight exposure to signal to our brains that it is time to wake up, as darkness descends in the evening, we are automatically programmed to want to sleep.
When we wake in the morning, our sleep drive is at its lowest. As we go through our day, we slowly accumulate this drive to sleep and when it reaches a certain threshold, we fall asleep. So, the longer you are awake, the stronger your drive to sleep becomes.
During sleep this need dissipates, and when we wake, the cycle starts again. When we are getting enough sleep, our circadian rhythm and sleep homeostat are working in balance.
But how much sleep per night do you need? Ask most people and they will likely put the figure at around eight hours. While this is a commonly-held belief and a good average, it is not necessarily correct; your sleep need is unique to you.
Our individual sleep need may be anything from 5-11 hours and is determined by many factors, including age, genetics, sex, environment and lifestyle.
In 2015, The National Sleep Foundation (NSF) published scientifically-based guidelines on the amount of sleep we require at each stage of our lives. They grouped sleep requirements into nine different age categories, as shown below3.
|Newborns||0–3 months||11–19 hours|
|Infants||4–11 months||10–18 hours|
|Toddlers||1–2 years||9–16 hours|
|Pre-schoolers||3–5 years||8–14 hours|
|School-aged children||6–13 years||7–12 hours|
|Teenagers||14–17 years||7–11 hours|
|Younger adults||18–25 years||6–11 hours|
|Adults||26–64 years||6–10 hours|
|Older adults||65 years plus||5–9 hours|
Babies and children most probably need more sleep as they are going through periods of rapid learning, development and skill acquisition, and long periods of sleep are needed to allow all these newly acquired skills to be consolidated.
Similarly, in our teenage years, with the onset of puberty, our circadian rhythm alters slightly, we develop rapidly and are still growing and learning, so need extra hours of sleep to maintain alertness.
Even as an adult, your sleep needs are not clear-cut. There is an inverse relationship between amount of sleep and increasing age; as we get older, we tend to sleep slightly less.
However, in the older adult age group, it is not the need for sleep that is necessarily decreasing, but the ability to get the required amount of sleep. Older adults often experience a shorter sleep duration due to existing medical conditions and the use of medication4.
Here at Sleepstation, we understand the importance of considering how your age impacts your sleep need when tailoring an appropriate sleep treatment to you.
Genetics undoubtedly plays a huge role in determining our sleep need. While some people are night owls, others are often up with the larks, and this is down to differences in genes regulating their circadian rhythms.
Variations in a group of genes called clock genes can cause our body clock to run faster or slower56. Differences in clock genes have also been shown to alter sleep drive1, while other genes have been identified that regulate sleep duration and influence how early certain people need to go to sleep7.
Variants have also been identified that result in very short sleep duration, where individuals need only 4–6.5 hours per night to meet their sleep need8.
You may think that you fall into this category, but these short sleeper variants are actually incredibly rare; less than 1% of the population can actually get by on such limited sleep. For the rest of us, we often believe that we are functioning well on very little sleep, when in fact we need much more to be at the top of our game.
Genetic testing is now helping to identify both genes that regulate our sleep and those associated with sleep disorders9 and it is certain that many more genes remain to be identified which control and regulate our sleep.
While we can’t change our genes, it can be reassuring to know that our sleep need is written in our individual genetic makeup. We often find ourselves feeling guilty when we sleep-in or feel too tired to do something, but by acknowledging that your body is pre-programmed to require a certain amount of sleep for you to feel at your best, you can do away with this unnecessary guilt.
The environment around you is an important influencer on your sleep need. As our circadian rhythm is highly regulated by sunlight, the seasons can affect how much sleep we require. In summer, we tend to rise earlier and sleep less, whereas in the cold and dark of winter, we want to sleep more.
Similarly, some cultures, especially in hot countries, still conserve a midday nap during the hottest months, which has an obvious shortening effect on the night-time sleep need.
Your lifestyle has a huge impact on your sleep need too. Highly active individuals, like professional athletes, will need more sleep than someone with a more sedentary lifestyle.
Likewise, a day spent in a high-pressure, busy job will require more sleep time than a day spent relaxing at the beach.
Over the past 30 years, sleep duration has decreased across most age groups. We live in an environment which embraces the notion of a 24-hour society; shift-working is considered normal and we spend more of our time now indoors, with lifestyles in which we are constantly exposed to artificial light from our devices and electric lighting. It is no surprise that at least a third of people are now thought to be sleep-deprived.
Sleepstation can help you to recognise factors in both your lifestyle and environment which may be impacting on your sleep and with our support, you will learn ways to improve your sleep and ensure that you are meeting your sleep need.
When we have a bad night’s sleep, we tend to assume that we can make it up the next night by sleeping longer. While this may work in the very short-term, having two or more nights of disturbed sleep in a row makes it impossible to make up what is lost.
Trying to catch up sleep at the weekend cannot replace getting regular, good-quality, adequate duration sleep.
While most people acknowledge that a healthy lifestyle, good diet and regular exercise are all necessary for maintaining our health, an adequate amount of sleep is equally as important, and is all too frequently overlooked.
There are certain simple steps you can take to try to ensure that you are getting enough sleep. An easy first step is to be mindful of how you feel; if you are waking up refreshed and able to go about your day without feeling sleepy, chances are your sleep need is met.
If you find yourself lacking in energy, not able to get out of bed in the morning and struggling with your day, you may not be getting the amount of sleep that is right for you.
Could you benefit from more sleep? Check your sleep score and find out how to improve it.
Sleep Function: Toward Elucidating an Enigma Krueger J, Frank M, Wisor J,and Roy S. Sleep Med Rev. 2016 Aug; 28: 4↑
Sleep homeostasis and the circadian clock: Do the circadian pacemaker and the sleep homeostat influence each other’s functioning? Deboer, T. Neurobiology of Sleep and Circadian Rhythms Volume 5, June 2018, Pages 68-77↑
Genetics of the human circadian clock and sleep homeostat. Ashbrook L, Krystal A, Fu Y-H & Ptáček L. Neuropsychopharmacology volume 45,2020 Pages 45–54↑
National Sleep Foundation's updated sleep duration recommendations: final report. Hirshkowitz M, Whiton K, Albert S, Alessi C, Bruni O, DonCarlos L, Hazen N, Herman J, Adams Hillard P, Katz E, Kheirandish-Gozal L, Neubauer D, O'Donnell A, Ohayon M, Peever J, Rawding R, Sachdeva R, Setters B, Vitiello M, Ware J. Sleep Health.2015 Dec;1(4):233-243.↑
Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Colten H, Altevogt BM.Institute of Medicine (US) Committee on Sleep Medicine and Research. Colten H, Altevogt B. Washington, DC: The National Academies Press; 2006.↑
Circadian rhythms in the CNS and peripheral clock disorders: human sleep disorders and clock genes. Ebisawa T. J Pharmacol Sci. 2007 Feb;103(2):150-4.↑
A non-circadian role for clock-genes in sleep homeostasis:a strain comparison Franken P, Thomason R, Craig Heller H, and O'Hara B. BMC Neurosci. 2007; 8: 87.↑
Sick and Tired: How molecular regulators of human sleep schedules and duration impact immune function Kurien P, Christin Chong S, Ptáček L, and Fu Y-H. Curr Opin Neurobiol. 2013 Oct; 23(5): 873–879.↑
Sleepiness as a Local Phenomenon D’Ambrosio S, Castelnovo A, Guglielmi O, Nobili L, Sarasso S, and Garbarino S. Front Neurosci. 2019; 13: 1086.↑
Genetics of Sleep and Sleep disorders Sehgal A and Mignot E. Cell. 2011 Jul 22; 146(2): 194–207.↑
Sleeping hours: what is the ideal number and how does age impact this? Chaput J-P, Dutil C, and Sampasa-Kanyinga H. Nat Sci Sleep. 2018; 10: 421–430.↑
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