💤 Why You Can Sleep 8 Hours and Still Wake Up Exhausted

Aug 29

This post is part of my Sleep Hygiene Series: Restful Nights & Restored Mornings.

Next up: [Evening Wind-Down Checklist for Restful Sleep] (coming soon)

The other night, I looked at my Apple Watch sleep chart and felt a little betrayed. It told me I had nearly 8 hours of sleep. On paper, that sounds like a win. But when I opened my eyes, I didn’t feel refreshed at all — I felt drained, achy, nauseous, and like I hadn’t slept a wink.

If you’ve ever had a “good” night’s sleep according to the numbers, but still felt exhausted, you’re not imagining it. The truth is, it’s not just about hours slept — it’s about sleep quality.

🌙 The Apple Watch Sleep Breakdown

On my chart, the night looked something like this:

Around 8 hours total of sleep
But only ~30–40 minutes of deep sleep (when the body does its deepest repair)
Just under an hour of REM sleep (when the brain processes memories + emotions)
The majority spent in core/light sleep

At first glance, it looked “fine.” But when we zoom in, we see why it didn’t feel fine at all.

🛏️ Understanding the 4 Stages of Sleep

1. Awake (red on the chart)

Everyone wakes up several times a night — to roll over, adjust, or use the restroom.
This usually totals 15–40 minutes across the night.
More awake time = more fragmented sleep, which leaves you foggy in the morning.

2. Core / Light Sleep (blue on the chart)

This makes up most of the night.
It’s important for rest and recovery, but by itself, it doesn’t restore you.
Think of it as “maintenance mode” — necessary, but not enough on its own.

3. Deep Sleep (dark blue on the chart)

The body’s true repair stage.
Muscles, tissues, and immune system get restored here.
You need about 1–2 hours per night for your body to fully recharge.
If you wake up achy or sore, you may not be getting enough.

4. REM Sleep (light turquoise on the chart)

This is the dream stage.
Your brain processes memories, regulates emotions, and balances your mood.
Adults usually need 90–120 minutes per night.
If you wake up mentally foggy or emotionally raw, it often means REM was cut short.

🌌 Why 8 Hours Didn’t Feel Restful

On my chart, I could see the problem clearly:

Core sleep dominated the night (good, but not enough).
Deep sleep was under an hour (short of the 1–2 hours we need).
REM sleep was also cut short (less emotional and mental restoration).

The result? Even with “enough” hours, I woke up exhausted because the balance between stages wasn’t there.

🌱 What Helps Improve Sleep Quality (Not Just Quantity)

Protect deep sleep: Cool room, avoid late-night heavy meals, keep a steady bedtime.
Support REM sleep: Lower stress before bed with journaling, prayer, or a calming tea.
Handle wake-ups better: If you’re awake at 2–3 AM, use a gentle reset routine instead of tossing and turning.
Track, don’t obsess: Use your Apple Watch as a guide, but also listen to how your body feels in the morning.