Full transcript
0:00You did everything right. You went to
0:02bed on time. You didn't scroll on your
0:04phone before bed.
0:06You got a solid 8 hours of sleep. So,
0:09why? Why do you feel so bad in the
0:11morning?
0:13You're groggy, disoriented, and
0:15completely exhausted whenever you wake
0:17up. The golden rule of 8 hours a night
0:19says you should be feeling rested,
0:21right? Well, maybe this rule isn't as
0:24golden as we thought.
0:25Sleep isn't just one continuous block of
0:29unconsciousness. It's a dynamic process
0:31made up of cycles.
0:33A typical sleep cycle lasts roughly 90
0:36minutes. During this 90-minute window,
0:39your brain moves through several stages.
0:41You start in light sleep, plunge into
0:44deep sleep, and finally enter REM, or
0:47rapid eye movement sleep, which is when
0:49you dream.
0:50Once a 90-minute cycle is complete, your
0:52brain goes back into light sleep, and
0:54the whole cycle starts all over again.
0:57So, here's where the 8-hour trap gets
0:59you.
0:59If you sleep for exactly 8 hours, your
1:02alarm is very likely going off right in
1:04the middle of a sleep cycle, often in
1:06the deep sleep [music] phase.
1:08When you are woken up out of deep sleep,
1:10your brain experiences something called
1:12sleep inertia. This is basically the
1:15heavy brain fog feeling that can take
1:17hours to shake off. You can sleep for 9,
1:2010, or even 11 hours, but if your alarm
1:23pulls you out of deep sleep, you will
1:24still end up feeling terrible in the
1:26morning.
1:27So, what's the fix? It's simple. Wake up
1:30at the end of a 90-minute cycle.
1:33When a cycle ends, your body is already
1:36in a natural, light stage of sleep,
1:39making it infinitely easier to wake up
1:41feeling alert and energized.
1:44Instead of aiming for 8 hours, try
1:47planning your sleep in multiples of 90
1:49minutes. For example, aim for 7 and 1/2
1:52hours, which is exactly five complete
1:54sleep cycles.
1:56If you're short on time, even 6 hours,
1:58which is four complete sleep cycles, can
2:00actually leave you feeling more
2:01refreshed than 7 or 8 hours of
2:04interrupted, fragmented sleep.
2:07So, the next time you need to wake up at
2:097:00 a.m., count backwards in 90-minute
2:12blocks.
2:13To get five full cycles, or 7 and 1/2
2:15hours, you'd want to actually fall
2:17asleep by 11:30 p.m.
2:20Add about 15 minutes to allow yourself
2:21to drift off, meaning lights out at
2:2311:15 p.m.
2:25Everybody's biological clock varies
2:28slightly, but if you're tired of waking
2:30up exhausted, ditch the 8-hour rule and
2:32start thinking in 90-minute cycles.
2:35Remember, how you sleep matters way more
2:38than how long you sleep. That's the key
2:40to better sleep.