What is the 'right' amount of Zzzz's each night?
Beyond making us tired and moody, sleep disturbances are often associated with impaired cognition, appetite dysregulation and a lowered immune function, as well as more serious consequences to our health such as an increased risk of obesity and certain chronic diseases.
Sleep deprivation is common among adults and is one of the most important components of our lifestyles. We often blame a lack of sleep for feeling exhausted – like you have been hit by a truck – not to mention turning us into grouchy individuals. Interestingly, not only is it a lack of sleep which may be contributing to a deficit in daytime functioning and an overall reduced quality of life, you could also be getting too much sleep!
Too much of a good thing?
The duration of sleep seems to be a ‘Goldilocks-like’ issue – with a balance between getting too little or too many hours sleep, but rather aiming for ‘just the right amount.’ This number will differ from person to person, as our sleep requirements vary across our lifespan. Last year, the National Sleep Foundation in the USA assembled a multidisciplinary panel to provide expert perspectives (from medicine, physiology and science) on sleep duration. Here are their results:
Expert panel recommended sleep durations:
| Age | Recommended | Not Recommended |
| Newborns 0-3 months | 14 to 17 hours | Less than 11 hours, more than 19 hours |
| Infants 4-11 months | 12 to 15 hours | Less than 10 hours, more than 18 hours |
| Toddlers 1-2 years | 11 to 14 hours | Less than 9 hours, more than 16 hours |
| Pre-schoolers 3-5 years | 10 to 13 hours | Less than 8 hours, more than 14 hours |
| School aged children 6-13 years | 9 to 11 hours | Less than 7 hours, more than 12 hours |
| Teenagers 14-17 years | 8 to 10 hours | Less than 7 hours, more than 11 hours |
| Young adults 18-25 years | 7 to 9 hours | Less than 6 hours, more than 11 hours |
| Adults 26-64 years | 7 to 9 hours | Less than 6 hours, more than 10 hours |
| Older adults > 65 years | 7 to 8 hours | Less than 5 hours, more than 9 hours |
Note: The recommendations represent guidelines for healthy individuals and those not suffering from a sleep disorder.
Our sleep requirements decrease until around 18 years, where they tend to stabilise throughout adulthood. Sleep duration outside the recommended range may be appropriate in some people, however, if you find you are routinely sleeping outside the recommended range, this could potentially compromise your health and wellbeing.
Even if you do obtain the recommended duration of sleep as an adult (e.g. 7-9 hours), it is also important to consider the time of the night you are falling asleep. The saying “an hour before midnight is worth two after” may hold some truth, as going to bed later in the night is likely to lead to a significant amount of your sleep being highly inefficient.
This is because our sleep cycle lasts 90 minutes, consisting of two different states of sleep known as non-rapid eye movement (NREM) and rapid eye movement (REM).
- NREM is a period where we transition from light sleep to a deeper slow-wave sleep. Slow-wave sleep is the deepest of the NREM phases and people usually have the most difficulty being woken. If you are disturbed during this time you may wake up feeling groggy.
- REM follows the slow-wave sleep and is a period of paradoxical sleep. REM sleep is associated with dreams, muscle atonia, as well as bursts of rapid eye movements and muscle twitches.
Most of our slow-wave deeper sleep occurs in the first half of the night and towards the morning our sleep tends to be lighter with longer periods of dreaming. So YES, sleep in the earlier hours of the night may be in fact worth more. Sleep and its restorative benefits are a vital part of physical, cognitive and emotional health, however life (and the stresses that come with it) can often get in the way and impede our ability for a good night’s sleep.
Tips for a good night’s sleep
If your mind is keeping you up…
- Consider stress-reducing activities – try some easy stretching exercises or yoga to relax your mind and muscles before bed.
- Have sex – it helps take your mind off things and the hormones produced help you relax and feel sleepy.
- Keep a journal – write down your thoughts or a to-do list to clear your mind until the morning.
- Sip on a herbal tea – a calming herbal tea such as chamomile or passionflower can assist in slowing your body before bed.
If you don’t feel tired (when you should…)
- Avoid technology and electronic devices in bed – artificial light can suppress melatonin production and affect your sleep cycle. Turn off all electronic devices at least one hour before bed.
- Participate in morning exercise – expose yourself to daylight first thing to help your natural circadian rhythm.
- Avoid consuming caffeine too close to your bed time.
- Catch the first sleep wave – listen to your body and go to bed when you feel drowsy (for most people this will occur between 9-10 pm).
Although both duration and the time we go to sleep is important, how you feel is a good measure to understand whether you are getting The Right Amount of Sleep. If you are concerned about your sleep, it is always best to discuss further with your healthcare practitioner.
