Ever fallen asleep at work?
Even just a quick little nod off before you snapped awake. Maybe, as I have, you’ve dropped off in a meeting, woken, and hoped your colleagues thought you were just concentrating…
If this is you, here’s a hack you might find useful.
The trick to a good nap is timing. You want to be a bit refreshed, while at the same time not too groggy.
Although it might seem counterintuitive, arranging a nap with a good hit of coffee is an excellent tactic.
Let’s look at coffee, or more particularly caffeine, then sleep, then join the ideas together.
We class caffeine as a stimulant but it isn’t actually the caffeine that does the stimulating. More accurately, caffeine binds extremely well with the numerous adenosine receptors in the brain, leading the brain to believe that it has plenty of adenosine and doesn’t require more.
Consequently, the brain doesn’t produce adenosine, and the normal effects of adenosine are overridden.
Adenosine is an inhibitory substance that, among other things, is responsible for promoting sleep, and inhibiting arousal. It’s a byproduct of the brain’s activities and builds up of a day.
So, if you don’t produce adenosine, you won’t promote sleep, and you won’t prevent arousal because you’ve removed an inhibitory substance, and you’ve let natural stimulants like dopamine and glutamate run amok.
Or in other words, you’ll feel more awake, more stimulated and more alert. Dopamine and glutamate are the stimulants, caffeine just releases the handbrake of adenosine.
Once you’ve had a coffee, it takes approximately 20 minutes for the caffeine to reach your brain.
Adults sleep in approximately 90 minute cycles, getting four or five cycles a night. Each cycle comprises two different types of sleep, which are probably familiar to you.
REM Sleep, short for Rapid Eye Movement Sleep, is one.
NREM Sleep, short for Non-Rapid Eye Movement Sleep, is the other.
NREM accounts for most of your sleep each night, and it’s further divided into different stages: Stages 1, 2 and 3.
Throughout the night, sleep follows a largely predictable pattern, looking something like this.
- Stage 1
- Stage 2
- Stage 3
- Stage 2
Between sleep and wakefulness, we’re reasonably easily woken, and we’re here for 5-10 minutes.
Brain waves are slowing and core body temperature is dropping, while we become increasingly harder to rouse. Stage 2 lasts up to 20 minutes.
About half of our time is in Stage 3, which is deep sleep. If we sleeptalk, sleepwalk, have night terrors or wet the bed, it’s usually in Stage 3. We’re especially hard to wake, and it’s most likely here that memories are consolidated.
The key characteristic of REM Sleep is obviously the rapidly moving eyes, clearly visible beneath the eyelids. The other key feature is a lack of muscle tone, so people are floppy and relaxed.
The interesting thing about REM Sleep is that the REM brainwaves look very much like those of an awake, alert brain, leading us to the nickname of paradoxical sleep.
About a quarter of our nightly sleep is in REM. Additionally, we spend more time in REM with each successive sleep cycle overnight. The last two, cycles four and five, are especially rich in REM. This is another reason we look for a good and full night’s sleep.
A little trick you need to know
Here’s a key to remember.
Sleep clears adenosine from the brain. Adenosine receptors then become available for competing substances, such as caffeine.
Sleep cycle optimization. With a caveat
Optimally, we need to aim for complete sleep cycles wherever we can. If this isn’t possible, next best is to aim for naps of approximately 20 minutes, as this is how long we’d usually spend in Stage 1 and 2, before we start to transition into Stage 3.
Once we get into Stage 3, we ideally need to get the whole cycle done. Otherwise, we’ll wake real groggy and take some time to fully wake up.
But the caveat is this. If you’re tired, and you just need to sleep, it can be awkward or impossible to get an optimal amount. 10 minutes might be all you can get. 90 minutes means you might lose your job!
So if push gets to shove, any sleep is better than no sleep, so if you need it and you can get it, then take it.
Yes, you might wake a little groggy, but this will pass.
Nap optimization: putting caffeine and sleep together
You now know that an ideal nap time is about 20 minutes.
You also know that caffeine takes about 20 minutes to hit your brain.
You know that sleep clears adenosine.
And you know that caffeine binds to adenosine receptors.
That’s a match.
This gives you a perfect 20 minute window of opportunity to grab some sleep and wake feeling pretty refreshed. By the time you’re looking to wake up, you’ve cleared adenosine from your brain by sleeping, and the caffeine is acting in your brain to give you a little jumpstart by filling the now empty adenosine receptors.
Good little hack, no?
Maximizing your optimizing
A couple of tips to make this the most effective.
Make sure you drink the coffee quickly. Otherwise, while you’re dawdling through your coffee it’s entering your bloodstream from your intestines, and making its way to your brain. Caffeine crosses easily through the blood-brain barrier and enters your brain where it begins to plug in to your adenosine receptors. By the time you put your head down, it might be most of the way there and will start working too early, negating what good effect you might have achieved.
You need also to ensure that it’s been some time since your last sleep. This won’t work if you’ve been up for only an hour or two. Usually we have a bit of a dip after lunch, in the siesta time. This is an excellent time for an optimized nap
So here’s the take home bit
For excellent performance, have a good quick cup of coffee, then nap for 20 minutes. You’ll wake up refreshed and sharper.
Impressive words to drop into the morning coffee chat
Adenosine, sleep cycle, NREM Sleep, REM Sleep
What do you think?
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