Why We Sleep

Puntos clave

• Dormir no es perder el tiempo: sostiene a todos los demás hábitos saludables
• Dos sistemas regulan el sueño: tu reloj interno y la presión acumulada al estar despierto
• El sueño profundo archiva recuerdos; la fase REM los conecta y les da sentido
• Dormir poco daña tus defensas, humor, peso y juicio mucho antes de que lo notes
• Constancia, oscuridad, frescor y menos cafeína o alcohol tarde resuelven casi todo

Dentro de este bit

1. El hábito base de todos los demás

   Picture a Mumbai commuter who gets home at 10 pm, scrolls until midnight, and wakes at 6 to do it again, proud of surviving on 6 hours. Matthew Walker, a sleep scientist, argues that this person is running a slow experiment on their own brain and body, and the results are not good.

2. Dos fuerzas deciden cuándo duermes

   Why do you feel sharp at 11 am and drowsy at 3 pm? Two separate systems are at work.

3. El sueño profundo archiva; el sueño REM conecta

   Sleep is not one state. Through the night you cycle between non-REM sleep, which includes slow-wave deep sleep, and REM sleep, where most vivid dreaming happens.

4. Lo que te cuesta dormir poco

   The damage from short sleep is broad and mostly invisible at first. After a few nights of 6 hours, your reaction time and attention fall to levels similar to being legally drunk, yet you feel fine because sleep loss also blunts your ability to judge your own impairment.

5. Soñar cumple una función real

   Walker treats dreaming as a serious biological function, not random noise. During REM sleep the brain becomes highly active while the body is paralysed, and the stress chemical noradrenaline drops to almost nothing.

6. Ponlo en práctica

   This week, fix a wake-up time and keep it on weekends too, because a stable clock helps more than any gadget. Move your last coffee or chai to before 2 pm and notice whether falling asleep gets easier.