Sleep. Some love it, some students just can’t seem to get enough, and others say it’s a waste of time. The truth is we all need it. Sleep is essential for maintaining cognitive ability and brain development. At night our bodies behave differently; our blood pressure and heart rate drop whilst our level of energy consumption remains broadly similar. Sleeping for 8 hours requires only 50kcal less than the same period spent awake – a very minimal difference. How detrimental then is sleep deprivation?

At the age of 17, Randy Gardner went without sleep for 264 hours. During this record breaking run he experienced hallucinations, paranoia and short-term memory loss. At the end of these 11 sleep-free days, however, he quickly recovered - after a mere 14 hour nap. The effects of sleep deprivation can’t be ignored though. After 17 hours spent without sleep, cognitive function is equal to someone with a blood alcohol level of 0.05% – that’s about two glasses of wine. So for those inclined to pull an all-nighter in the attempt to finish an essay, bear in mind that your proof-reading skills might not be up to scratch. Figures often suggest an ‘optimum’ or ‘ideal’ amount of sleep for our bodies, but in reality this varies between individuals. One proposed surrogate for sleep requirements is the length of time it takes you to fall asleep: between 10 and 15 minutes is ideal. Less than five minutes and you’re probably sleep deprived, over fifteen and you might consider waking up more regularly for 9am lectures.

We all have that friend or sibling who sleeps a lot. If you don’t, it’s probably you. But you can cut yourself some slack. Research shows that while humans are still developing they not only need more sleep but also prefer to sleep and wake later. The hormone melatonin is key in helping our bodies to fall asleep – research suggests that teenagers and young adults produce the hormone up to 3 hours later in the day than fully- grown adults. Teenagers could just be misunderstood, not lazy. Unfortunately for the late- night essay writer, the typical undergraduate student age group – 18-24 – is thought to be more susceptible to decreased function as a result of sleep loss.

It’s also possible to get enough sleep but not in the right pattern. A recent sleep study suggests that a solid eight hours isn’t beneficial or natural – instead, we should have two four- hour bursts. The researchers claimed that we have been socially programmed to sleep eight hours a night, but that historical records indicate we are naturally more inclined to two distinct shorter naps. The historian Roger Ekrich of Virginia Tech has published a paper of 500 historical references pointing to segmental sleeping. In addition, prayer manuals from the 15th century often included prayers specifically for in-between sleep. Thomas Wehr, scientist emeritus at the US National Institute of Mental Health, found further support for segmental sleeping - he plunged his test subjects into darkness for 14 hours a day for a month. By the end everyone was sleeping for four hours, waking for a couple, before returning to sleep. So next time you’re wide-awake in the middle of the night, don’t worry, it’s nothing to lose sleep over.

• The discovery of REM - Rapid Eye Movement – sleep was delayed. Researchers hadn’t wanted to waste the paper on comprehensive overnight recordings.
• One in every six car accidents are estimated to be caused by fatigue
• You burn more calories in sleep than you do when watching television. 1⁄4 of the UK population suffers from a sleep problem
• A proven link has been established between insomnia and your bedroom environment: turn your phone and laptop off!