Why do some people feel sleepier after drinking coffee?

As urban white-collar workers, getting up with a cup of coffee every day is our basic accomplishment.

But why do some people become energetic after drinking coffee, while others feel nothing at all? Why do some people feel energetic for hours after drinking coffee, while other times they fall asleep right away after drinking coffee? Today, let's take a look at the secrets of caffeine.

flickr / Thomas Listl

01-The mechanism of caffeine's action: preventing adenosine from binding to adenosine receptors

First, let's look at how caffeine works. It doesn't actually make your brain more excited, but it prevents your brain from getting sleepy.

The two components in your brain that are responsible for making you sleepy are adenosine and adenosine receptors. They are like a plug and a socket. Once plugged in and powered on, the activity of your nerve cells will weaken, which in layman's terms means you'll feel sleepy.

Adenosine (blue) binds to receptors, and people feel sleepy |

As for caffeine, it can also be plugged into this socket, but it cannot be powered, so adenosine, which is responsible for making you sleepy, has no place to generate electricity. So although the body will continue to produce adenosine when it is tired, it cannot be plugged into the adenosine receptors because it is blocked by caffeine, so people will continue to be awake and excited.

Orange represents caffeine, which blocks the binding of adenosine to receptors |

02-Why do I feel sleepier the more I drink?

So under what circumstances does caffeine not work? There are actually many reasons, but the most important ones are the following:

? Genetic determination

The principle we just explained mentioned adenosine receptors, and everyone's adenosine receptors have different sensitivities to caffeine, which is determined by genes, so some people are naturally immune to caffeine. You may need to drink a whole cup to achieve the same effect as others can achieve with just one sip.

Another genetically determined factor is the rate at which coffee is metabolized. Some people can stay awake for a whole day after drinking coffee, while others can only stay awake for an hour or two.

If you happen to be the type who is insensitive to caffeine and metabolizes it quickly, then basically no matter how much coffee you drink, it will be useless.

flickr / Giuliano Griffante

? Drinking late

Let's go back to the working principle of caffeine we talked about above - it actually prevents adenosine and adenosine receptors from using love to generate electricity. But if adenosine and adenosine receptors have already combined when you drink it, then caffeine becomes the awkward party and can't grab the socket.

So at this time, caffeine has to stand aside and watch adenosine make us sleepy.

flickr / olle svensson

? Drink too much

Another possibility is that long-term and large amounts of coffee drinking can lead to tolerance, which can reduce the number of adenosine receptors released in the brain. This is why some people become "coffee addicts", from being energetic after one cup to being unable to open their eyes after two cups.

? Too much sugar in coffee

Most people drink coffee with sugar in it: vanilla latte, caramel macchiato... and three-in-one instant coffee with extremely high trans fat content.

Many coffees contain sugar | flickr Linnea P

Sugar can also make you excited, so when you first drink sweetened coffee, you may be excited. But the insulin in your body will quickly go out to help you lower your blood sugar. The sudden drop in blood sugar will make you feel sleepy, and sometimes accompanied by headaches, lack of concentration, dizziness and other symptoms.

flickr / Keith Survell

03-How can you drink to be more sober?

We have already explained the specific reasons why caffeine doesn’t work above, so just break them down one by one.

? Coffee Nap

This is a method that has been proven to be effective by scientists. Sleeping can reduce the fatigue of the brain, unbind adenosine and adenosine receptors, and thus allow caffeine to take advantage. How to do it?

Because caffeine can stay in the human body for 4-5 hours, and the Coffee Nap we are talking about should not exceed 20 minutes.

So the best way is to drink a cup of coffee 20 minutes before going to bed, so that the caffeine is ready. It’s okay if you can’t fall asleep in these 20 minutes, just close your eyes and try to let your body and brain rest for 20 minutes, adenosine will slowly leave, and then the caffeine can work.

Have a cup of coffee before going to sleep | flickr daimak

? Drink in advance

Coffee nap is only useful as a last-ditch effort, but if possible, it’s better to drink it in advance to ensure that caffeine takes over the adenosine receptors.

If you need to stay alert in the afternoon, drink coffee at noon; if you need to be alert in the morning, drink it early in the morning.

? Try to drink less

To avoid coffee addiction and tolerance, control your coffee intake no matter how sleepy you are. It is best not to exceed 2 cups a day.

Try to limit yourself to 2 cups of coffee a day | flickr Mami WI

Because caffeine can only temporarily prevent adenosine from binding to receptors, but cannot eliminate adenosine, coffee is actually just "prepaying" your energy, and the payback will always come. Therefore, rest is the best way to maintain energy, and coffee is best used for emergency.

If you have become tolerant to caffeine, it is recommended that you "quit" it for a while, otherwise no matter how much you consume, it may not satisfy you in the end.

? Drink less coffee with high sugar content

The high sugar content in coffee can easily make you go up and down on a roller coaster of wakefulness and sleepiness, and three-in-one instant coffee is a typical example. In addition to the accumulated adenosine waiting to take revenge on you, the increase and decrease of blood sugar levels will make you even more sleepy, so it is better not to drink it.

So if you want coffee to work, it's best to drink low-sugar or sugar-free coffee.

If you want to be awake, you need to control your sugar intake | flickr kendra k

So caffeine is the life-saving medicine for office workers...