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Sleep, although often not prioritised in our busy lifestyles, has irrefutable benefits for our overall health and wellbeing. It is an essential physiological process that plays a crucial role in maintaining our physical, mental, and emotional health. Let’s look further into the science behind sleep:

What makes a ‘good’ sleep?

A ‘good’ sleep is one that refreshes you and helps to give you the energy to get through the day. Good sleep does not mean 8 hours solid as it is normal to wake up a few times during the night and/or have occasional nights when sleep is hard to obtain or maintain. According to Professor Simon Smith of the University of Queensland, good sleep may be considered in the following four ways:

  1. Sleep duration: how many hours were slept?
  2. Quality: how good was it?
  3. Timing: do your bedtime and wake-up time suit your lifestyle?
  4. Regularity: when does your body clock determine your sleep?

Sleep duration:  

People need different amounts of sleep and recommendations vary depending on age.

Adults: Most require between 7 and 9 hours per night.

Teenagers: Need between 8 and 10 hours of sleep per night.

Children aged 6-12: Typically need 9 to 12 hours of sleep per night.

Toddlers: Require 11 to 14 hours of sleep per night. 

Our circadian rhythm is our body’s natural sleep cycle, dictating when we sleep. Teenagers’ circadian rhythm is different to children and adults – they prefer to stay up later and sleep later in the day (as any parent of a teenager will know when trying to wrestle them out of bed and off to high school!).

Research has found that people who get five hours of sleep or less per night, have increased risk of getting two or more chronic diseases as they get older. Whilst the risk is relatively low, it is important to be mindful of the importance of sleep and to prioritise sleep quantity and quality.

Quality sleep:

There are five different stages of sleep.   

Stage 1: Dozing or drowsiness in between being awake and being asleep.

Stage 2: Falling asleep, loss of awareness, body temperature drops, and breathing and heart rate slow down. Memories form in this sleep stage.

Stage 3: Deep or “delta sleep” – fully asleep, blood pressure, heart rate and breathing become very slow and muscles are relaxed. Energy is restored in this stage.

Stage 4: More deep sleep – growth and repair processes occur during this stage.

Stage 5: REM sleep. This stage is most associated with dreams and memory consolidation. The brain is very active in this stage. Muscles are essentially paralysed (leading some people to experience “sleep paralysis”) while breathing may be faster. REM sleep occurs about every 90-120 minutes and forms about ¼ of total sleep. This sleep stage is important for emotional processing and forming new memories.

As above, all five stages of sleep are important for the restoration and rejuvenation of our body, as damaged tissue is repaired, energy stores are replenished, and our hormonal balance is regulated. Muscle growth occurs during sleep, immunity is boosted, and heart health is enhanced. Our brain benefits too – sleep helps us consolidate memories, process information, and enhance learning, attention, and concentration. Obtaining sufficient sleep enables us to cope better with stress and regulate emotions. Sleep deprivation, on the other hand, can impair memory, productivity, and cognitive function, whilst we might also find that we are more irritable and/or mood swings and increased anxiety. Alcohol, drug use, or poor or insufficient sleep can negatively impact on well-being because we may not achieve the REM sleep stage at all.  

If you struggle with sleep, it is important to see your doctor to rule out any significant causes. Psychologists may be able to assist you with mindfulness and relaxation activities as well as with managing stress or other causes of poor sleep.

Adapted from:

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Sharon Connell

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