Counting Sheep

Sometimes the loftiest goal of all is achieving eight hours of shut-eye. janet forman gets some prescription zzzzzzs as she investigates the science of sleep.

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YOU KNOW THAT splendid sensation on awakening from a solid eight hour sleep: brain firing on all cylinders, body and spirit ready for action? I think I’ve experienced it approximately twice, since – like most of us in this 24-hour work world with deadlines to meet, time zones to cross, and electronics bleating for attention – I’ve always regarded sleeping eight hours a night an endeavour best pursued in retirement, like reading Proust. Then scientists started poking around the somewhat neglected field of “sleep science” and turned up some disquieting data.

Sleep deprivation has become an epidemic. In 1910, before Edison’s light bulb went mass market, historical notes say people slept nine hours a night. Today we average less than seven, and recent research says optimum health calls for between seven and a half and eight. This small difference is crucial, experts maintain, since repairing the physical and mental stresses of the day requires five full sleep cycles of 90 to 100 minutes. Every cycle has four stages, each performing a dedicated task: deep sleep, for example, repairs physical damage and restores the immune system, and REM – or dreaming sleep – supports mental and emotional functions. Doctors now find that losing just one hour a night for a week is like pulling an all-nighter, and sleep lost on a regular basis creates a debt, which, like the credit-card variety, can become cumulative.