Do we need sleep?

There is still no real explanation of why we need sleep.

As you arrive at work on Monday morning tired, are you thinking I didn’t get enough sleep this weekend?

How much sleep is enough? Is it best to have one big sleep, or lots of little ones?

A report in the current issue of New scientist (2647) looks at research on sleep in mammals and tries to extrapolate from their behaviours why we may need sleep. Unfortunately there is still no real understanding of why we need it. It doesn’t appear to make sense from an evolutionary point of view- why do giraffes only need 3 hours a day, but lions need 12- 14 hours?

One lecture at the R.I. I went to on sleep explained how sleep is necessary for cognitive recovery, but that simply doing nothing is enough for physical recovery.

That makes the afternoon nap important as it allows for your brain to recover from the activity of the day so far, process the information, and then you wake up being better able to focus on what needs to be done.

I know that being chronically sleep deprived (thanks to my daughter) does mean that I am less able to concentrate on cognitive tasks. You may experience this as a result of work or exam deadlines.

In the short term you may get by, but over a period of weeks or months, you will suffer from a performance slump. The most sustainable way is to have good quality sleep, with a short nap when you need a break. Unfortunately this may be frowned upon in the UK as slacking, or not driving the Protestant work ethic forward.

Further reading

• Effect of acute sleep deprivation 
• How much sleep do I need after training?