Ever found you're still exhausted after seven – or even nine – hours sleep?
Scientists at Brigham and Women's Hospital in Harvard University may have uncovered why...
(If you're a student reading this, we advise you look away now...)
As The Telegraph reported, a study conducted at the Ivy league school showed that if you don't go to sleep at a regular time you may not reap the rewards a good night's sleep would otherwise offer.
Why is this? Well, when you go to bed at different times – 10pm one night, 3am another (like students are wont to do) – your body's circadian rhythm (that's your body clock, responsible for telling you when to sleep, get up, eat) gets out of kilter.
This means your body releases melatonin (the hormone that regulates sleep) at irregular times, making it harder to get to sleep – or stay awake – on demand.
Power naps do nothing to solve this, sadly. However, there is one silver lining. You can make up for less hours' sleep by simply regulating the time you go to bed...
As Dr Charles A. Czeisler, Director of the Sleep Health Institute at Brigham and Women's Hospital, said: 'For the students whose sleep and wake times were inconsistent, classes and exams that were scheduled for 9am were therefore occurring at 6am according to their body clock, at a time when performance is impaired.
'Ironically, they didn't save any time because in the end they slept just as much as those on a more regular schedule.'
The study monitored 61 undergraduates at Harvard over 30 days and found that those who said 'nighty-night' at the same time each evening actually outperformed those who got into bed at random times. Which we think is pretty compelling.
We're setting our 'GO TO BED' alarm for 10pm every night and darn well sticking to it.
p.s. Now, about that after party...