Extra, later sleep on weekends = teen jet lag in school

A study of approximately 2,700 upper secondary school pupils, aged 13-16 shows that teens sleep longer at weekends. And because they go to bed later and wake up later, they turn up for school with a changed sleeping cycle. In other words -- they suffer from jet lag.

For some, it may take three to four days to get back into routine -- and by then, the school week is nearly over. But for the large majority, the weekend-related jet lag is not a big deal. Almost all teens in the study did suffer from jet lag, but a majority of them did get enough sleep during the week.

But 20 per cent of those taking part in the study on the whole did not get enough sleep.