This is because alcohol is an anesthetic. And the human body will tend to wake up after an anesthetic wears off. I believe the anesthetic properties of alcohol lasts roughly 4 hours, so if you sleep you'll probably begin to stir and wake up 4 hours after your last drink. Very similar to surgery patients who naturally wake up after the anesthetic used for surgery wears off.

That's just how sleep works. Everyone's REM sleep cycles last 90-120 minutes.

https://www.howsleepworks.com/types_rem.html

4 hours for me like clockwork after a few drinks before bed.

This is crazy but I'm pretty similar, is this a documented effect that I could read more about?

Almost always after a night of heavy drinking I wake from anywhere between 5am - 8am and have a rough time getting back to sleep for at least a few hours. Knowing my drinking patterns, those times would tend to correlate to about 4 hours earlier passing out.

This happens to many people in around the same timeframe, I'm pretty sure it's due to GABA rebound https://www.nature.com/scitable/blog/mind-read/alcohol_sleep...

From what I recall, alcohol binds to GABA receptors, GABA builds up in the body, eventually metabolizes to glutamate which takes a few hours depending on how much you drink, but seems to be around half a night's sleep. The glutamate wakes you up and gives you energy, hence the strange "feeling great after a night of drinking on no sleep" thing.

Anecdotal, but my fitbit gave me the same result.

Every single time I had drunk - even 1-2 - there was a spike of restlessness that night, 10-20 restless periods vs the 3-4 I would have normally.

Ya, I just got an apple watch a couple of weeks ago and noticed this as well. It's crazy - ~4 hours of deep sleep on a normal night and 1.5-2 on a night where I've had even just a single drink

What app did you use? I want to try this also.

Not OP but I use Autosleep. Works well.

Also autosleep