Some people have a hard time sleeping at nights and just cannot wake up in the mornings. This could be because their body clocks are set very slow.
A team from Flinders University in Adelaide, Australia, are trying to find out about delayed sleep phase disorder, which is a characterized by a consistent inability to fall asleep in the nights and not being able to wake up at a regular time in the mornings.
This could be due to out of sync internal body clock. 'Late sleepers can't get to sleep until 2am or 3am at the earliest, or in some cases as late as 4am, which makes it very hard for them to get up for their commitments the next day. Most people have a 24-hour body clock, it's a natural rhythm that influences sleepiness and core body temperature but for people with delayed sleep phase disorder it takes longer to complete the cycle so they tend to go to bed later and wake up later,' researchers said.
When the body is exposed to bright light in the early morning, it is a signal to the body that it should be awake. Light levels, flying across time zones and working during night shifts affects the body clock.
Most living beings follow the circadian rhythms and this is a daily cycle ruled by our internal body clocks. This has a bearing on the sleep and wake cycles, body temperature and the release of hormones.