A closer look
You think you are tired because of work, but really your cells are aggressively embezzling your daily energy intake. About a fifth of all the calories you consume go straight to tiny molecular bouncers called sodium-potassium pumps. Their entire existence revolves around violently kicking sodium ions out of the cell and dragging potassium ions in, creating the electrical gradient needed for every thought and muscle twitch. They are the microscopic vampires keeping your nervous system functioning.
