The exact time you need to go to sleep to wake up feeling refreshed at 7am

SLEEP is perhaps more complicated than just simply hitting the sack and then waking up the next morning refreshed – or so the latest research would indicate.

The important thing to keep in mind, apparently, is a sleep cycle.

Rather than simply getting more sleep when you’re tired, you need to get in tune with your sleep cycle – and if you wake up in the middle of a sleep cycle rather than at the end you might actually feel more tired even if you slept for longer, so the latest findings from blinds.com indicates.

A sleep cycle last approximately 90 minutes and during that you are meant to move through five stages of sleep.

Four of those stages are non-rapid eye movement (NREM) and one stage of rapid eye movement (REM).

The first stage is a light sleep and then you fall into a deeper and deeper sleep as you move through the stages.

As stage four is a deep sleep if you wake up at this stage in the cycle then its more than likely you’ll feel groggy.

The fifth stage is REM and is when you supposedly dream.

So using that as a basis, if you need to wake up at 7am to start the working day then you need to go to bed at either 9.46pm or 11.16pm.

If neither of those appeal then 12.46am or 2.16am would also be best.

These precise times take into account the average of 14 minutes it takes people to fall asleep naturally.

Similarly, if you need to wake up at 6am the optimal times to go to bed are 8.46pm, 10.16pm, 11.46pm or even 1.16am.

If you have to wake up at 8am then bedtime should be at 10.46pm, 12.16am, 1.46am or even 3.16am.

The website says: “Getting a good night’s sleep is about more than simply going to bed early – it’s about waking up at the right time too.

“Using a formula based on the body’s natural rhythms, the Sleep Calculator will work out the best time for you to rise or go to sleep.”