HOW MANY HOURS SLEEP DO YOU NEED?

Keep a notebook by your bed at night for a week. Note down:

The time you get into bed.

Each time you wake in the night, make a mark on the paper.

In the morning, note down the time you wake.

Once fully awake, estimate how long it took you to get to sleep, and how long you were awake during the night for each waking. Deduct all the time you were awake during the night from the number of hours you spent in bed. You now have the total time you spent asleep. Divide this figure by the total time in bed (from climbing under the covers to getting up in the morning). This is your sleep efficiency. So if you get 0.7, for example, this is an efficiency of 70%. Add up the total time you spent asleep over the week, and divide by seven. This is your sleep quota, the amount of time you need to spend in bed. To work out your new bedtime, count back from the time you need to wake up. So if your sleep quota is seven and a half hours and you need to be up at seven, go to bed at 11.30pm. This time may be later than your current ‘bedtime’.