Much has been said about the importance of getting enough sleep. Far from being a luxury – although some people seem to treat it as a nice-to-have – sleep is an essential time for the body and mind to recover from everyday challenges, for cell repair and growth and for the brain to flush out toxins.
Restorative sleep helps to keep your nervous, hormonal and immune system functions in balance. It’s a virtuous circle, with sleep right at the centre that affecting every part of your health. Sleep deficiency, on the other hand, is linked to an increased risk of high blood pressure and heart disease, stroke, diabetes, kidney disease and many other serious diseases.
But how much sleep is healthy? And scratching beyond the recommended headline figure of 8 hours per night, isn’t the quality of your sleep as important as the quantity?
According to the National Sleep Foundation, sleep can be divided into non-rapid eye movement (NREM) and rapid eye movement (REM) sleep; the two alternative in roughly 90-minute cycles throughout the night. The cycle goes as follows:
About ¾ of our nightly sleep is spent in NREM.
Light sleep (approx. ½ of total sleep) starts with that relaxed half awake / half asleep state (N1) before you nod off properly. Twitching is common and you can be woken up easily. The second stage of light sleep (N2) is when you start to become disengaged from the external environment, your muscles relax, your heart rate, breathing and body temperature drops. You are now well and truly asleep.
Deep sleep is the third NREM stage (N3). It’s the most healing and rejuvenating sleep stage, where muscle growth and repair occurs. It’s difficult to wake someone from deep sleep – the person will feel disoriented and groggy as they adjust to being awake again.
Deep sleep is often hailed as the holy grail of good sleep – after all, it’s where most restorative processes take places. According to the American Sleep Association, “deep sleep is an important part of our nightly sleep cycle, in which our bodies repair themselves and build up energy for the next day. It’s where the release of growth hormones occurs in children and young adults, aiding the body’s maturation process. Deep sleep is also when tissue repair occurs, and when your body detoxifies itself.”
That said, the amount of deep sleep can vary substantially between individuals, and between nights too, adding up to anywhere between 0 and 1/3 of your total night’s sleep. For adults, the average is about 15-20%.
As we get older, we naturally spend less time in deep sleep. The production of HGH (Human Growth Hormone) peaks in youth and steadily declines with age.
The remaining quarter of the night’s sleep is spent in REM, although the figure can be anywhere between 5-50% and usually decreases with advancing age. After a period of deep sleep, the body slips back into N2 before entering REM sleep.
REM sleep plays a key role in re-energising body and mind. It is regulated by your body clock and is associated with dreaming, with memory consolidation, learning and creativity. Increase your chances of getting more REM sleep by avoiding artificial stimulants before bed, having a regular sleep schedule and getting a full night’s sleep.
Finally, the time spent before/after you fall asleep is called awake time. This includes the time it takes you to drop off at bedtime, and night time wakings – both of which can be used to evaluate your sleep quality. Unsurprisingly, difficulties with falling or staying asleep at night are typically linked to daytime sleepiness.
How to increase your deep sleep?
Deep sleep is the body’s best chance to heal itself at the cellular level. Particularly for anyone with a chronic illness, deep sleep is essential to repair damage and build replacement tissue such as skin or bone cells. Without ample opportunity to fix your ailments and help to keep your skin, bones and organs strong, not only will you age at a faster rate, it will become harder to fend off illness and disease.
If you’re worried about the small amount of deep sleep you’re getting, there’s a few things you can do:
1. Cultivate healthy sleep habits
Your behaviour during the day can have a major impact on your sleep quality. In order to promote healthy sleep patterns, keep a consistent sleep schedule including regular bedtimes, aiming for at least 7 hours of sleep per night.
Make your bedroom a relaxing sanctuary that’s used only for sleeping and sex, and keep any electronic devices out of the room. Ensure that the temperature is cool yet comfortable and reduce your fluid intake just before bed. Finally, if you’re keen to increase the amount of deep sleep you’re getting, more/regular physical activity, avoiding naps and caffeine in the afternoon and heavy meals and alcohol before bed, are said to be among the best strategies.
2. Examine your mattress
In order for the body to reach the deep sleep stage in the sleep cycle, it has to pass through several stages of sleep without interruption. One of the most common sleep disruptors is an unsuitable or uncomfortable mattress. If you’re not getting enough deep sleep, it is highly recommended that you check your mattress is still fit for purpose.
If you decide to buy a new mattress, look for optimal spinal alignment and distributed support at key pressure points for your particular size and body shape. Whether you choose a pocket sprung, memory foam or latex mattress, it may be the best investment into your health you can make. If you’re unsure about what type of mattress will be best for you, take a look at this helpful guide from Snug Interiors.
3. Speak to your doctor
If you are suffering from chronic sleep problems that won’t seem to shift, a trip to the GP may be a good idea. Sometimes, sleep problems can be a symptoms of an underlying medical condition and your doctor is the best person to investigate and advise.
Getting enough sleep is important for your health, with quality deep sleep helping your body to repair and grow. If you find yourself tossing and turning at night make sure you consider your health, sleeping habits and environment. Are there things you can do to try and improve your slumber, and get the best possible night’s sleep?
Annie Button is a Portsmouth based writer. Annie likes to share her experiences and knowledge through her articles and has written for a variety online and print publications. When she’s not writing Annie likes cooking healthy new recipes and relaxing with a good book.