Why does drinking coffee refresh people when they are sleepy?

In our life, many people come to drink coffee to help them relieve fatigue. Especially when people feel very tired, they will drink coffee or tea to refresh themselves. In many western countries, coffee is a common drink. Due to the popularity of coffee, the output of coffee beans has been increasing. Why can coffee be loved by so many people? Why can coffee have some refreshing effect? Let me explain below.

Coffee can relieve people's fatigue because it contains a special thing, that is, caffeine. Coffee is made from coffee beans, which are now produced in many countries. Coffee bean is a common tree species in some low-latitude countries, and coffee bean export is the main industry in many countries. Coffee beans are rich in caffeine, and it is the role of caffeine that makes coffee have a refreshing effect. According to the research of scientists, caffeine has a certain stimulating effect on human body. After caffeine enters the human body, it can stimulate the blood in our blood vessels to change quickly, which can make people's heart beat faster to some extent. From these two aspects, caffeine has a very significant refreshing effect. When people feel sleepy, proper heartbeat acceleration and heart rate increase will make people feel a little excited, which is the role of caffeine. At that time, the effect of caffeine was not very prominent for some people, which contained some individual differences. Some people's reaction to caffeine is not obvious, so coffee becomes a common drink. Drinking some caffeine in moderation has a certain effect on treating cardiovascular diseases and improving arteriosclerosis. In people's daily life, coffee is also a way to adjust lifestyle.