Sleep is about recovery, both for your body and your brain. In the first hour and a half of deep sleep, you release human growth hormone and begin the process of resetting your adrenals.
The brain doesn’t have a lymphatic system to flush toxins. It goes through a process of washing itself with cerebrospinal fluid four times a night to cleanse itself of toxins.
Without deep restful sleep these processes cannot happen. Sleep varies between individuals but it’s well known that 7 hours seems to be the magic number. Sleeping longer may be fine on occasion but it doesn’t make up for missing sleep on a regular basis.
The best sleep is consistent deep sleep. If you’re hitting the pillow and not stirring until you wake up, it doesn’t matter if it’s 6, 7 or 8, you’ll be fine. When it comes to sleep, quality beats quantity.