transcript: Tired? We all know the feeling; irritable,
groggy, and exceptionally lazy. Chances are you didn’t sleep enough last night...or
the past few nights. But what exactly is ‘enough sleep’? And more importantly, can you ever
‘catch up’ on it? While the very function of sleep is still
debated by scientists, we do know that it's necessary to function efficiently and productively
- after all we spend 24 years of our lifetime sleeping, it’d better be important. Researchers
have tested how much is required each night, by assigning groups of people to 4, 6, and
8 hours of sleep over extended periods of time. After 14 days, those with 8 hours of
sleep exhibited few attention lapses or cognitive issues; however, those with 6 or 4 hours of
sleep showed a steady decline. In fact, after only 2 weeks, the 6 hour group showed a similar
reaction time to a person with a blood alcohol concentration of 0.10% , which is considered
legally drunk. The 4 hour sleepers suffered even more, occasionally falling asleep during
their cognitive tests. In both groups, brain function decreased day by day, almost linearly
with no sign of leveling off. Scientists have dubbed this cumulative effect
as sleep debt. So can we recover from it? After a night or two of little sleep, studies
show that the body and brain can fully recover with a few nights of good sleep. However,
with long term sleep deprivation on the scale of weeks to months, the recovery of cognitive
function is much slower, requiring many more nights of quality sleep. On the timescale
of months to years, it is unknown whether brain function can be fully repaired, or if
it causes permanent damage. Paradoxically, with chronic sleep deprivation, your sleepiness
or how tired you feel does eventually level off, meaning that you become less and less
aware of your objective impairment over time. So how long should you sleep? Most studies
tend to show that 7-8 hours of sleep is the average ideal for humans. Apart from the cognitive
issues, individuals who consistently sleep less than 7 hours a night have an increased
risk of heart disease, obesity and diabetes - not to mention a 12% higher risk of death.
On the flip side, studies have shown that while sleeping more than 8 hours does not
impair brain function, it also carries an increased risk of heart disease, obesity and
diabetes and a 30% increased risk of mortality! So too much sleep may also be a bad thing. But variation most certainly exists - and
our genetics play a large role! In fact, individuals genuinely unaffected by only 6 hours of sleep
were found to have a mutation of a specific gene. When scientists genetically engineered
mice to express this gene, they were able to stay awake for an extra 1.2 hours than
normal mice. It turns out these short sleepers have more biologically intense sleep sessions
than the average person. Ultimately, while it’s important to know
the ideal average of 7-8 hours exists, let your body and brain help you figure out its
own needs. After all, no one shoe size fits all. If you want to know how to get better
quality sleep each night in order to conquer the hurdles of sleep deprivation, we have
some tips and research for you over on AsapTHOUGHT - you can find a link in the description below
to that video! Thanks to Audible.com for giving you a free
audio book of your choice at audible.com/asap. Audible is the leading provider of audiobooks
with over 150,000 downloadable titles across all types of literature. We recommend the
‘A Song Of Ice And Fire’ series which the Game Of Thrones TV show is based off of.
It’s kept us up through the nights and caused a lot of lost sleep! You can download this
audio book or another of your choice, for free, at audible.com/asap. And with a subscription
you get one free book a month, so you can read the whole series! Special thanks Audible
for making these videos possible! And subscribe for more weekly science videos!
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