Why I sleep

What are some myths you’ve heard about sleep? More hours equate to good sleep? Waking up in the middle of the night is a bad thing? Or maybe, daytime naps are unhealthy? Thankfully, these are just myths.

Good sleep is characterised by the following factors: there are no factors that make up good sleep for every single person because sleep quality is a subjective experience

HOWEVER, there are a few things to consider when talking about sleep. (Note. Please consider the following to be general advice. With everything we know about sleep, a single blog post wouldn’t be enough time to cover it. I will address some sleeping concerns, but please seek further advice if you’re experiencing sleep issues.)

Sleep is as essential to the human body as oxygen and water. It is defined as the ‘naturally recurring state that is marked by reduced or absent consciousness and sensory activity, as well as the inactivity of most voluntary muscles’ (Reference: News Medical Life Sciences).  

You’ve probably heard that adults should be sleeping 7-9 hours. Where does this number come from?

 Sleep is measured in sleep stages. A single sleep stage is around 90 minutes long and adults should get between 4-6 sleep stages a night. Therefore, 90 min x 4-6 sleep stages = 360 mins- 540 mins = 6hrs-9hrs.

However, the number of hours is less important than the quality of your sleep, which is informed by the sleep cycles and how much time you’re spending in deep sleep. Research indicates that deep sleep needs to be about 25% of your total sleep time. This is why some people can sleep for ten hours and wake up feeling drowsy, and others who can sleep for 6 and wake up feeling great. (Note that there are some medications and other life factors that can impact deep sleep quality.)

Your body is biologically driven to sleep. There are two main internal biological mechanisms that work together to tell your body when it is time to sleep and when it is time to wake up. These are called circadian rhythms and sleep wake homeostasis.

Circadian rhythms 

This is best known as the clock that is in line with the 24 hour day cycle. It's the biological clock that is synchronised with the outside environment (with the sun being the biggest light source). Daylight exposure increases sleep duration and quality, and sunshine has been found to play a role in regulating hormones. Your circadian rhythms, also impacted by sunshine, control the timing of sleep, when you get sleepy, when you wake up etc through body temperature, release of sleep hormones and wake hormones and metabolism. These rhythms are responsible for the release of melatonin, a hormone that is released to help you feel sleepy (and can be taken orally for those who may not produce as much). Melatonin production is important to help the body’s circadian rhythm match the external light/dark cycle. 

Sleep-wake homeostasis

Homeostasis refers to any self-regulating biological process that works to keep stability within the body. The sleep wake homeostasis process works to make sure the body sleeps after a certain time of being awake and wakes the body after a certain time of being asleep.

So, in a perfect world, the moment you wake up would be the moment you have the least need for sleep. Your circadian rhythms have released the wakeful hormones, the sun is shining through your room and you’ve had a solid 5-6 sleep cycles. From this moment, every hour you are awake, is working towards creating your sleep drive. 

If you imagine every hour going into a sleep bucket, the fuller the bucket is when the environment is getting dark and sleep hormones are being released, you are more likely to fall asleep quicker, easier and sleep in time with your circadian rhythm.

HOWEVER

Every time you do something that takes OUT of your sleep bucket, i.e. caffeine intake after a certain time, napping, staying awake past the point of sleep time as per your circadian rhythms, your body is more likely to fall asleep later. You may be less tired because you’ve compromised some of your need for sleep. This can lead to less sleep, more tiredness, more coffee, more naps, being awake at night, starting the cycle again, leading to bad habits, which in turn can lead to a host of physical and mental issues. 

This sounds dramatic but in Australia, more than half of the adult population are experiencing ‘at least one chronic sleep symptom that is affecting their ability to live a healthy, happy life’ (The Sleep Foundation). 

Sleep is one of the best (and easiest ways) to improve your quality of life, without doing anything at all 😏