Most of us have heard that eight hours of sleep is ideal for a rested body and mind. However, not only do some people need more or less than that, but a review of studies from this year suggests that keeping our circadian rhythm in check may be more key to preventing exhaustion than getting enough hours each night. Hannah Shore, a sleep scientist at Mattress Online , agrees that staying in tune with your “body clock” is crucial to feeling rested. That’s why she says it’s so important to avoid switching up your wake time. You should try to wake up at the same time every morning “Our bodies run on lots of different rhythms; some of these involve chemicals which help the sleep/wake cycle,” Shore told HuffPost UK. “When we are awake, our bodies produce wake-promoting hormones, such as cortisol, to help keep us alert and active. “When we sleep, our bodies produce sleep-promoting hormones, like melatonin, to help us fall asleep and stay asleep.” But, she added, these cannot be produced at the same time. That means you’ll probably struggle to nod off if your body is actively producing wake-promoting hormones. “By keeping the time of your sleep regular, your body will start to know when to produce the right hormones at the right time of day, making it easier to both fall asleep and wake up,” Shore stated. Some research suggests that sleep regularity , rather than just its duration, is “critical” for mental health too. Which is more important: going to bed at the same time or waking up at the same time? Ideally, you’d fall asleep and wake up at roughly the same time every night. But, Shore said, if you have to pick one, go for a regular wake-up time. “If you are trying to get your timing right, start by getting up at the same time every day,” she said. That’s because, she claimed, it’s “easier to wake yourself up than it is to force yourself to sleep”. (And yes – I regret to inform you that this does apply to weekends , too). Related... If You Sleep In The 'T. Rex Position,' We've Got Some Bad News For You A Doctor Uses These 3 Numbers To Tell Bad Sleep From Insomnia The First Technique A Sleep Expert Tries After Waking Up At 3AM