[relyks]

Basically, caffeine is bad for sleep (learning and recovery) if taken late enough and significant amounts remain in your system at bedtime. It does note that even having a coffee first thing in the morning does have a measurable effect on deep sleep brain waves. Fast metabolizers of caffeine might be different. Don't drink coffee in the afternoon is probably the take away for most people

[Loughla]

Old people love coffee late in the day.

Grandpa used to wake up at about 2 in the morning to pee, and would have a cup of coffee before going right back to sleep.

So maybe the effects nullify after a certain point?

[temp0826]

I've never been able to fall asleep easily. When I see someone who instantly can, I wonder if they are chronically exhausted from a lifetime of bad sleep. I know it's probably not the case but it kind of makes me jealous.

[lolinder]

That he was able to go back to sleep with caffeine in his system doesn't show anything at all about the quality of that sleep.

[kimixa]

Any my brother seems to function having a coffee only a couple of hours before bedtime since he was 18. If I do the same I'll not sleep at all and feel terrible the entire next day.

The question is more about would you function better in some way without that, and how much effects vary over the populace.

[Gigachad]

Caffeine in low doses doesn’t really seem to have any effect for me. Or at least not an acute noticeable effect. I drink coffee out of habit and because I like it. But if I’m on holidays and don’t have access to it, it doesn’t bother me in the slightest.

[potato3732842]

Old people drink decaf

[MisterBastahrd]

Have ADHD. Caffeine slows my brain down and I can fall asleep directly after having consumed a half-pot of coffee.

[msephton]

Same here! If I really can't sleep a small sugar-free high-caffeine energy drink is as good as a sleeping pill.

[dgfitz]

This must be my diagnosis. I can smash 3 cups of coffee and conk out in 15 minutes.

[Nathanba]

caffeine seems to accumulate though, very soon it won't matter how late in the day you took your coffee today because there is still some amount in there from yesterday too. Personally I'm trying to drink as little coffee as possible now, sleep is too precious. I cannot risk having this constant negative health impact on my life.

[Multiplayer]

I am a massive caffeine drinker. Like many of us, I monitor my sleep religiously so I have an anecdote. Late afternoon espresso or hot coffee is usually quite sleep effecting.

However - I have found that cold brew does not bother my sleep! At least the brand that I drink. Very strange, but awesome. Cold brew does not have the acidity of hot coffee which is a double bonus if you get acid reflux at night from poor eating or drinking habits. Give it a whirl.

[makeitdouble]

I think it will wildly vary depending on how regular your life cycle is.

As an anecdote I also tried tracking my sleep, only to realize:

- consumer trackers are wildly inaccurate (best we can do is compare them to a "medical grade" reference tracker, which might be accurate or not, who knows)

- there was so many other things going on every day, pinning it down to even two or three factors was just impossible (e.g. I drink more coffee when I have more time to make it, which is related to my stress level and work volume etc.)

- watch data were a PITA to export and analyze separately. I did it twice or thrice and didn't bother after that.