We all know the basic rules to getting enough sleep: try and catch 7-8 hours most nights, avoid using your phone or watching telly just before bed, don’t drink too much caffeine - and so forth.

Except…it turns out that’s not quite the case.

According to National Geographic’s documentary Sleepless in America, there’s one simple sleep habit we all need to adopt:

Waking up at the same time every day (yes, even at weekends).

National Geographic instructs people to “Keep to a regular sleep schedule. Try to go to bed and get up in the morning at the same time every day, even on weekends. According to NSF (the National Sleep Foundation), this helps to regulate your body’s internal clock and could improve your chances of getting a sound sleep.”

Your body’s circadian rhythm will learn when it is time for you to go to bed and when it is time for you to wake up – so it naturally begins to slow down at bed time and prepare for waking in the morning.

That means that our old friend, the snooze button, is actually our worst enemy.

When you press snooze in the morning, your body isn’t getting the valuable restorative sleep that will make you feel better, it is just messing up your circadian rhythm and confusing your natural body clock which will only serve to make you feel sluggish and grumpy – both for the immediate future and in the long-term.

When your body knows what time you’ll be getting up, it begins to help you with the waking process. Before waking, sleep becomes lighter and neuro-signals tell your body temperature to rise, and increase levels of cortisol which encourages your brain to become more alert.

If you’re constantly pressing snooze or waking up at different times each day, your body can no longer predict your wake-up time and help you to wake up naturally.

Waking up at different times and snoozing every morning also means that you are highly likely to pull your body out of a sleep cycle, which can result in a feeling of grogginess for up to 4 hours.

It also means your body doesn’t know when to make you feel sleepy at night, so you might not make it to bed on time and will feel more tired in your day-to-day life. (This study seems to ignore anyone who does shift work – sorry guys).

So, making sure you wake up at the same time every day will make you feel more alert and energetic on a daily basis.

Professor Lauren Hale from the Stony Brook Medicine Program of Public Health, says: "I know people who set their alarm 30 minutes earlier than it needs to be, so they can have an extra half hour of restless sleep in which they are regularly having to check the clock. Who wants that?! You want your sleep to be as deep and uninterrupted as possible. Hitting the snooze button after you first hear your alarm isn't going to help you get the deep restorative sleep that you are seeking. "

If you struggle to wake up in the morning (don’t we all?) it might also be time to reassess your pre-bedtime activities. National Geographic have these 10 handy tips for getting a good night’s rest, here.

Words: Harriet Hall 

Images: Rex Features