The main factor that coffee can refresh is that it contains caffeine, which can dock with the receptor that receives the fatigue signal of the brain, so the brain can't know the signal transmitted by the fatigue substance.

But caffeine can only last 1-2 hours in the body, so it can't be said that you won't be sleepy after drinking coffee, but you will be energetic for a while. Coffee can promote metabolism, so it can eliminate fatigue to some extent. Tip: Don't drink too much. Drinking too much coffee is similar to stimulants, causing sweating, palpitations and tinnitus in the palms. Many people show that they will skip it quickly after drinking coffee. Blood pressure will rise if you take it for a long time. If you are in a serious mood, the risk will multiply. Therefore, people at risk of hypertension should especially avoid drinking caffeinated drinks when working pressure is high.