Margaret Thatcher famously ran the country for 11 years on just four hours’ sleep, while Dante reportedly wrote the Divine Comedy on uncontrollable naps lasting no more than a few minutes.
And while we’ve all heard about the quasi-mythical figure of eight, many of us need up to ten hours in bed at a time. The truth is that there is no such thing as the perfect night’s sleep – just what suits the needs of each individual.
What is clear, however, is that everyone’s sleep is made up of the same key elements; a cyclical series of phases that must be successfully completed to enjoy a good night.
So, what are these patterns? Sleep can be broadly divided into two types: non-rapid eye movement (NREM), which is broken up into three further phases, and rapid eye movement (REM). And they follow this pattern:
• The first phase of NREM – indeed the first stage of sleep – is when the muscles are still active and the eyes move slowly.
• Once the second stage of NREM is reached, it becomes harder to wake, with the brain working overtime to keep the body feeling tranquil.
• At the third point of NREM, the body is deeply sleeping in a state of log-like bliss.
• Next sees a return to the second phase of NREM, as sleep’s hold ever-so-slightly lessens.
• And then comes REM – the hardest point to wake from and yet the phase when the brain is working in a similar way to during the day.
The cyclical nature of sleep means that we pass through all the stages every 90 minutes until morning, when – fingers crossed – we wake up refreshed and ready to go.