British specialists together with colleagues from the United States conducted a number of studies and proved that drinking coffee shifts the human biorhythms for 40 minutes. The experiment involved volunteers who agreed to be in special rooms without the ability to turn off the lights.
Subjects received tablets of caffeine, scientists were monitoring the situation and watched how many people can stay refreshed on the most popular stimulant in the world.
It turned out one Cup of coffee in the evening or night shifts biorhythms for 40 minutes, stirring the body to sink into the sleep state. Interesting is another fact. Bright night lighting has the same effect.