You wake up, and the first thing you do is have a cup of coffee.
Many people probably have this habit.
Lately, you may also have come across the idea on social media that “the best time to drink coffee is 90 minutes after waking up.”
So, is this true?
To get straight to the point, it is not the case that “90 minutes after waking” is absolutely right.
However, there is a scientific line of thinking behind this idea.
In this article, we look at the relationship between coffee and sleep.
Why “90 Minutes Later” Gets Attention
When we wake up in the morning, our bodies release a hormone called cortisol.
Cortisol is sometimes called the “stress hormone,” but it is not a bad thing in itself. It plays important roles such as
• Waking the body up
• Regulating blood pressure and blood sugar
• Switching the body into active mode
and more.
For a while after waking, cortisol levels are naturally high, which means your “wake-up switch” is already on.
For this reason, some researchers believe you may feel the effects of caffeine more easily if you drink coffee once cortisol levels have settled down.
This is where the “90 minutes after waking” idea comes from.
“90 Minutes Later” Has Not Been Proven
On the other hand, current research has not proven
that “90 minutes later is always the most effective.”
Cortisol levels and daily rhythms vary from person to person, and they also change depending on
• What time you wake up
• How long you sleep
• Your body clock
and other factors.
So drinking coffee right after you wake up does not mean it is bad for your health.
It is best to think of “90 minutes later” as just a rough guideline.
What You Really Need to Watch for Your Sleep
In fact, what matters more than when you drink coffee in the morning is caffeine in the afternoon and beyond.
Caffeine is known to stay in the body for a long time, with a half-life generally said to be about 2 to 8 hours.
This means it is not unusual for caffeine from coffee you drank in the early evening to still be in your body at bedtime.
As a result, it may affect your sleep quality, for example by
• Making it harder to fall asleep
• Reducing deep sleep
• Making you more likely to wake during the night
and so on.
If you “have trouble falling asleep at night” or “still feel tired in the morning,” you may notice more of a difference by reviewing your afternoon caffeine than by worrying about your morning coffee.
Sleep Quality Changes with Daily Habits
In moderation, coffee is a reliable drink that boosts concentration and alertness.
On the other hand, depending on when and how much you drink, it can also affect your sleep.
There is no need to get too caught up in the “90 minutes after waking” rule, but reviewing how you enjoy caffeine to suit your own daily rhythm can be a good step toward better sleep.
At La HEAD, too, guests sometimes tell us that “my sleep is light” or “I can’t wake up feeling refreshed.”
Making small changes to your daily habits may lead to more comfortable days for both mind and body.