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  • I know this happened to you, too.

  • You wake up at 7 a.m. and you feel refreshed.

  • You decide to sleep in for 2 more hours, and when you wake up at 9 a.m., you feel like crap.

  • How come those extra 2 hours, instead of energizing you, they actually made you feel worse?

  • Well, first we need to understand how our sleep works, so we can figure out how to manipulate it and wake up alert and refreshed.

  • Our sleep is made of three stages.

  • The first stage is called "light sleep."

  • This is right after you go to sleep.

  • Any sudden noises may awake you, and people often report that they feel awaken when sleeping in this stage.

  • The second stage is "deep sleep" or "Delta Phase."

  • This is where we sleep most deeply.

  • The last stage is called "REM Sleep" or "rapid eye movement sleep."

  • This is the stage where we dream.

  • Our eyes dart back and forth beneath closed lids and our muscles temporarily shut down to prevent us from acting out dreams.

  • After the REM sleep, we enter the first stage, light sleep, and the cycle repeats.

  • The whole cycle takes around 90 minutes to complete.

  • So if you were sleeping for 9 hours, that means you've been through 6 sleep cycles.

  • The reason we feel groggy and tired, is when we wake up in the middle of the cycle.

  • So if you want to feel refreshed, find out when you want to be awake, then count backwards in 90-minute blocks.

  • For example, if you need to wake up at 7 a.m., you should aim to be asleep at 11:30 p.m.

  • That's 7 and a half hours of sleep, or 5 cycles. Of course, you can plan for 6 or 9 hours of sleep, but that depends on you.

  • And also, the common belief that we should sleep for 8 hours per night is actually wrong, because it does not align with our sleep cycles.

  • So, if you want to never again feel tired or groggy in the morning, and if you want to wake up alert and refreshed, keep in mind the 90-minute rule.

  • Anyway, don't forget to subscribe, and thanks for watching.

I know this happened to you, too.

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