Who does not know: The night was somehow too short and you feel tired and tired. In the dark season and in icy temperatures, this phenomenon is exacerbated. For many the first and best remedy for fatigue: the coffee in the morning. He is par excellence for many. But does coffee really wake us up?

Why are we getting tired?

When we wake up, the neurons (nerve cells responsible for the transmission of information) in our body signal to the brain, “Wake up and stay awake!”. At the same time, however, another substance is being produced – the organic molecule “adenosine”. Adenosine makes us tired. On the one hand, it prevents the release of wakeful substances such as dopamine. Second, it reduces heart rate and lowers blood pressure by dilating blood vessels. These are signs of a resting phase for our body.

After drinking coffee, we feel more alert and more efficient. But how is it?

As just described, the substance Adenosine makes us feel tired. In the body, this feeling works with the “key-lock” principle: the “key” adenosine attaches itself to a receptor, the “lock”. He opens the lock and so a signal is sent to our brain that makes us tired. When we drink coffee, the caffeine in coffee acts as a block. It blocks the place of adenosine, but does not trigger its action, so no signal is sent to the brain.

In addition to this blockage, caffeine also ensures that other (invigorating) substances work better.

How long does coffee keep you awake?

If caffeine prevents us from getting tired, the question is, how long can I stay awake with caffeine? Everyone knows from experience that even if you drink coffee all the time, you will eventually get tired. But if caffeine prevents you from getting tired, why do you get tired at some point? That’s because of the tolerance that our body has over caffeine. How high this tolerance limit is depends on the coffee consumption of the individual. The more caffeine the body is used to, the higher the tolerance – just like other substances. Someone who has been drinking several cups of coffee a day for years, probably no longer wakes up after a cup of coffee.

How long does the effect of coffee last?

The caffeine in coffee begins to work after about ten to sixty minutes. Depending on the amount of consumption, tolerance and other influencing factors such as gender, age and health condition, the effect of caffeine persists for about three to five hours. However, most coffee drinkers, even those with moderate consumption, will agree that the duration of their effects usually seems much lower and that they will soon grab the next coffee.