Why 8 Hours Isn’t Always Enough: What Really Defines Quality Sleep

Most of us know that adults need an average of 7-9 hours per night (National Sleep Foundation, 2023). But if you’re still waking up groggy, struggling with brain fog, or getting sick despite hitting that number, the issue might not be how long you’re sleeping, it’s how well you’re sleeping.

This is where your sleep architecture comes in. The structure of your sleep across different stages: light, deep, and REM. Each stage supports different parts of your physical and mental recovery. 

Deep sleep

This is your body’s most restorative stage. It supports tissue repair, immune function, and energy restoration. Most deep sleep happens in the first half of the night, and stress, caffeine, and alcohol can all reduce it. It should be 16-33% of our overall sleep.

Light sleep

Light sleep serves as a bridge between deep and REM stages. It plays a key role in memory processing and cellular maintenance. If you’re not getting enough, you might feel mentally sluggish or have trouble focusing. It should be 30-64% of total sleep.

REM sleep

REM (rapid eye movement) is when most dreaming occurs, and it supports learning, creativity, and emotional regulation. Most REM happens in the last half of the night, which is why consistent wake times matter. Avoiding alcohol and heavy meals close to bedtime can help to boost REM sleep. It should be 21-31% of our total sleep.

Awake time

It’s normal to wake briefly several times per night, but extended wake periods can reduce the time your body spends in restorative stages. Fragmented sleep can make even eight hours in bed feel like six.

Why are knowing about these stages important? Because while you may be in bed sleeping for 8 hours, you may not be getting an adequate amount of a certain stage OR you may not actually be asleep for those 8 hours. 

Devices such as smart watches (Garmin, Apple) or fitness trackers (Whoop band, Oura ring,  FitBit) can provide us with the sleep data that we need. 

Simple ways to improve your sleep architecture:

-avoid eating or drinking alcohol for a few hours before bed

-exercise regularly, but avoid intense exercise before bed

-get outside within the first hour of waking to help regulate circadian rhythm

-having a consistent sleep and wake time

Getting enough quality sleep is a cornerstone of good health. Getting enough quality sleep improves a long list of health metrics and is well worth the effort of prioritizing. Happy Zzzz’s!