According to a report from Brown University Health Education, caffeine helps to “stimulate the adrenal gland gland to produce more adrenaline”, thus leading to noticeable increase in strength and performance in drinkers.
The video below explains that caffeine occupies the same receptors of our brain as adenosine, also known as the “sleepy hormone”.
So basically, whenever we consume caffeine, less adenosine can reach these receptors – making you more awake and alert!