Own the Day, Own Your Life: Optimized Practices for Waking, Working, Learning, Eating, Training, Playing, Sleeping, and Sex

by Aubrey Marcus

When you’re dehydrated and have nothing in your stomach, the caffeine enters your bloodstream incredibly fast, releasing a flood of stress hormones from your adrenal glands that your body reads as a fight-or-flight trigger. Like you’ve been woken up being chased by a predatory cat. While this is effective in the short term, it’s generally a good rule of thumb to keep aggressive caffeine and feline doses to a minimum first thing in the morning. Drinking caffeine when you are dehydrated may feel good for the mouth, but you aren’t exactly digging out of the hole. The hydrating water in the coffee is somewhat offset by the dehydrating nature of caffeine. Yet we still reach for coffee in the morning, in large part because these adrenal effects are so damn good at dealing with the other problem we face when we wake up: we’re still tired.