A lot of people dread the clocks going back an hour in winter—but reassure themselves that at least they'll get an extra hour's sleep. However, in my new study, my colleagues and I found most people do not (or can not) take advantage of the full extra hour of sleep in autumn. Daylight saving time is the practice of moving the clocks one hour forward in spring and one hour back in autumn.
It was introduced during the First World War as a way to cut energy costs. It is in operation in around 70 countries and affects a quarter of the world's population. This "springing forward" and "falling back" is widely thought of as a loss of one hour of sleep in spring and a gain of one hour of sleep in autumn.
However, research suggests we may lose sleep for about a week after both clock changes, as we struggle to adapt to the new time. Previous studies have relied on people reporting their own sleep patterns in diaries or surveys . However, this may not be accurate because people sometimes forget or lie about how long they slept for.
Recent research has overcome this problem by using activity monitors to record people's sleep over the clock changes. But until now, researchers have only been able to do this in a small number of people. Our new study explored the effects of the clock changes on objectively-measured sleep duration in a large number of people who are signed up to the UK Biobank .
This is a research database with lifestyle and health information from half a million UK partic.
