Written by Matthew Walker

Neglecting sleep undercuts your creativity, problem solving, decision-making, learning, memory, heart health, brain health, mental health, emotional well-being, immune system, and even your life span.

Why do we sleep? After all, when you’re sleeping—and all animals do—you can’t hunt, gather, eat, reproduce, or defend yourself. Yet Walker concludes that the evolutionary upsides of sleep are far greater than these downsides. In brief, sleep produces complex neurochemical baths that improve our brains in various ways. And it “restocks the armory of our immune system, helping fight malignancy, preventing infection, and warding off all manner of sickness.” In other words, sleep greatly enhances our evolutionary fitness—just in ways we can’t see.

Wakaing up forced =bad for heart, snoozing extra bad

Avoid blue light at night

A natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (is endogenous) and responds to the environment. of teens is shifted forward, there are also differences in people. 40% of ppl are morning persons, 30% night owls

Smart heating and lighting will help circadian rythm

Sleep enough in the week before your flu shot

If you can possibly take a short midday nap like our ancestors used to and some Mediterranean and South American cultures still do, you should (but no later than 3 pm). It will likely improve your creativity and coronary health as well as extend your lifetime.

Accidents caused by drowsy driving are more dangerous than those caused by intoxication

1 Stick to a sleep schedule (set an alarm for bedtime)