|DO IT SOON||What’s up? If sleeping is meant to be restful, why do we feel so damn tired when we wake up?|
|What’s new? It’s called “sleep inertia”. The causal mechanism is a lack of cerebral blood flow when you wake up.Studies show that if you wake up while in deep sleep, you’re going to have worse sleep inertia. When you wake up in deep sleep, you often feel more tired: It’s like when you wake up to catch that flight before dawn and you feel like you have no idea where you are. If you wake up at the wrong time of a nap, you also feel that way, because the first sleep cycle you go through is very rich in deep sleep, and you’re probably waking up in the middle of that.
If you sleep a healthy amount-ideally 8.5 hours-you’re getting almost no deep sleep by the end of your sleep, as the amount of deep sleep reduces over the course of the night. That means you’re less likely to wake up in deep sleep if you’re well rested, and therefore less likely to feel groggy. If you didn’t have a good night’s sleep, it’ll take longer for you to wake up.
|So what? Get your 8.5 hours a day; it’s the new 8 hour sleep.|