You may be in love with your morning coffee ritual, but have you ever wondered what this relationship is really about? Coffee and its principal stimulant, caffeine, can affect the body in a number of ways. Sure, you already know that it helps transform you from a miserable morning beast into a semi-decent member of human society — but what else is going on in there? Here are three surprising side effects of your coffee habit that affect your body, inside and out.
Sharpens Your Vision
That morning fog that seems to loom everywhere before you hit your first cup o’ joe? You’re not imagining it. Caffeine stimulates adrenaline production — the same type of hormone used in fight or flight reactions used by our ancestors to escape predators. Your heart rate speeds up slightly, you become more alert, and your pupils dilate, all of which help you deal with that oncoming bear attack (or 8:00 a.m. meeting agenda).
Boosts Your Metabolism
Coffee lovers have the brown stuff running through their veins — sort of. Caffeine increases the speed of blood flow throughout the body, which in turn helps deliver oxygen to muscles to help them work more efficiently. If you’re an athlete, caffeine might help you go longer, faster, or harder. If you’re a couch potato, your metabolism will get a boost even while you binge Netflix.
Makes You Poop

MetaFilter