A solid amount of deep sleep in a night is the main reason why we feel fresh in the morning.
A lack thereof makes us feel hit by a car. It decreases our capabilities during the day. It’s also linked to playing a role in the development of mental diseases such as Alzheimer’s.
Luckily, there is a simple way to increase deep sleep duration instantly, without any practice.
I don’t want to bother you with definitions and technicalities. Here are just some basics.