Do you really need 8 hours of sleep?
The answer is yes, you do need 8 hours of sleep per night. However, recently we ran a survey to find out how much sleep you get and the results showed that the majority of you get less than 6 hours sleep! Today I'm going to focus on key points about why you need 8 hours of sleep, including:
- Where did these sleep recommendations come from?
- The health benefits of 8 hours sleep
- Do you really need 8 hours of sleep?
- How to improve your sleep.
Where did these sleep recommendations come from?
So, where did this recommended sleep time come from? The answer seems to lie in an experiment conducted by Thomas Wehr during the 1980s and 1990s. This experiment involved plunging the participants into darkness for 14 hours every day for a month. As you would expect, it took a while for their sleep patterns to regulate but, by the last week, the subjects had settled into a routine whereby they slept 4 hours before awakening for 1 or 2 hours and then going back to sleep for another 4 hours.1
This pattern then seemed to have merged with the idea of getting 8 hours of sleep each night, with any period of wakefulness during the night being perceived as an unfortunate sign of insomnia or sleep deprivation.
The health benefits of 8 hours sleep
I'm sure that many of you will have experienced fatigue, lack of concentration and moodiness after a poor night's sleep. However, there can be much more serious health implications of lack of sleep.
Firstly, efficient sleep can help to maintain a healthy immune system. During sleep your body produces and releases cytokines (proteins that regulate the body's immune response). If you are regularly losing out on sleep your body will produce fewer cytokines, putting you at risk of developing a cold or flu.
Secondly, as I have mentioned in many previous blogs, efficient REM sleep has been associated with improving your memory and concentration. If you do not get enough sleep you may find yourself feeling sluggish the next day and find it hard to concentrate.
Thirdly, there is a direct link between stress and sleep. When the body is under stress, the autonomic nervous system releases both adrenaline and noradrenaline. This can cause you to toss and turn at night before eventually falling asleep. On the other hand, a good night's sleep may help to control your body's stress response system.2
Finally, having a good night's sleep can have a positive impact on your mental health. Serotonin is produced during REM sleep and it should be produced daily. It is often referred to as our feel-good hormone, and research has found that there is a direct link between low serotonin levels, poor sleep and low mood.3
The above evidence suggests that 8 hours of sleep is beneficial to your physical health as well as your mental health. Although sleeping time is individual, it is recommended that you get at least 8 hours of sleep per night. Below, I have included a handy table of The National Sleep Foundation's recommendations for sleep time.4
|New-borns (0-3 months)
||14-17 hours per day
|Infants (4-11 months)
||12-15 hours per day
|Toddlers (1-2 years)
|Preschool children (3-5)
|School age children (6-13)
|Older adults (65+)
How to improve your sleep
Below, I have listed some good sleep hygiene practises that may help you to get a better night's sleep:
- Limit day- time naps to 30 minutes – Napping does not make up for a poor night's sleep! However, according to the National Sleep Foundation, napping for 20-30 minutes can help to improve your mood.5
- Avoid caffeine and alcohol before bed time – These have a negative impact on sleep. Have a look at my blog "5 simple ways to prevent sleep deprivation" for more information.
- Limit your screen time before going to sleep - The blue light from screens (mobiles, tablets, computers and televisions) decreases melatonin production. Try to reduce your screen time before going to bed to ensure that you produce enough melatonin to help you fall asleep. Have a look at our Nutritionist Emma's blog "Which hormones make you feel tired" for more information.
- Develop a relaxing bedtime routine – Try going for a warm bath. Recent research has suggested that bathing one to two hours before bed in water at 40 to 43°C helps you to fall asleep around 10 minutes faster than you normally would.6 Or try reading a book before going to bed. Reading is a calming activity and research has found that reading before bed can help to reduce stress.7
- As I mentioned above, there is a direct link between stress and sleep, and reduced stress may help you to sleep better.
- Participate in day-time exercise - During exercise, your brain produces more endorphins. These feel- good neurotransmitters reduce pain and boost pleasure, resulting in a feeling of well-being. Endorphins have been directly linked to reducing stress and anxiety.
- For more good practises of sleep hygiene, have a look at my article "Sleep hygiene tips".
- 90% of people recommend Dormeasan for a good night's sleep.
So, what can you take away from this blog?
It is recommended that you get at least 8 hours of sleep per night since this has a positive impact on both your physical and mental health. If you are struggling to get enough sleep try to practise good sleep hygiene or, if you are worried about not getting enough sleep, speak to your doctor.
Originally written on 31st January 2018, updated on 31st December 2019.