Expert shares why we wake up tired even after eight hours of rest

'Most people don’t know that the time you get up in the morning affects the time you will be able to fall asleep that night,' she told Whimn.

'When we see bright light in the morning our brain switches off the production of melatonin and it is this off-switching that actually sets up our 24 hour body clock.'

The problem with this is it throws out your bodies circadian rhythm which has serious side effects.

Not resetting your biological clock at a regular time each morning not only effects your sleep but will also effect your hunger and will have an impact on bathroom cues while decreasing your skills and motivation.

As consistency is the main sleep secret it is important to have both a strict wake up time and bed time.  

'Both are important as they dictate the total amount of sleep someone gets,' Dr Harrington said.

'However as our getting up time plays a role in what time we are ready to sleep that night, a regular wake up time is probably more important.

'For this reason it's recommended that you don't vary your wake-up time by more than an hour.'

As well as ensuring you have a good sleep routine you also need to make sure you're getting enough sleep, but different people need different amounts.

Previously Daily Mail Australia spoke with Sealy sleep analyst Dr Amy Reynolds about the importance of a good quality snooze during different stages of your life.

'Sleep patterns certainly change over time. What doesn't change is the crucial need for a routine and good "sleep hygiene" as we call it,' Dr Reynolds said.

Our constant access to phones and the internet can inhibit our bodies ability to get good quality levels of sleep so it's important to turn all electrical equipment off an hour before hitting the hay.

According to a Sealy sleep survey 70 per cent of Australians feel their everyday performance is affected by lack of sleep.

'People studying at university or working, typically between the ages of 18 and 25, should be getting 7-9 hours of sleep a night,' Dr Reynolds explained.

There should also be a bedtime routine for mums just like there is a system in place for young children.

'Women between the ages of 26-60 should be getting around 7-9 hours of sleep a night. Try to get everyone in the family into bed at a reasonable hour by brushing your teeth together and reading a bedtime story,' Dr Reynolds said.

'Women over 60 can get 7-8 hours of rest a night and remain perfectly healthy.'

In terms of trying to 'make up' for lost sleep Dr Reynolds said you should instead aim for the recommended amount each night - 'topping' up on sleep isn't effective.

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