In general tea leaves, the caffeine content accounts for about 2-4% of the dry tea. The caffeine in tea can also combine with tea polyphenols, thus being slowly released in the human body. Therefore, drinking tea is more mellow and refreshing than coffee, and its stimulating effect is not as strong as coffee. Some people call tea a gentle stimulant. About 2 minutes after the tea is brewed, about 70%-80% of the caffeine has already dissolved in the water. Drinking tea at this time has a noticeable refreshing effect. As the tea steeps longer, the tea polyphenols gradually dissolve into the water, counteracting the effect of caffeine and significantly reducing the refreshing effect. So if you want to use tea to refresh yourself, remember not to steep the tea for too long, otherwise it may inhibit the excitement of the brain nerves and have a calming effect.

Many drivers like to drink strong tea or coffee to refresh themselves, but frequent consumption of strong tea or coffee can lead to tolerance over time. The development of tolerance inevitably leads to an increase in the consumption of strong tea or coffee, which in turn can damage Yin fluids due to excessive diuresis.

Therefore, drivers should try to drink plain water, adjusting to cool or warm plain water based on the weather and their physical condition. The best way to refresh oneself is to force a rest, even if it is brief; after resting, one will naturally feel refreshed.