When youâ€™re awake a chemical called adenosine is produced, which binds to the receptors in your brain. This actually slows down your brain activity, making your brain feel more tired and leading you to feel fatigued throughout the day.
The First Cup
Caffeine functions similarly to adenosine, as it works its way into your bloodstream, binding with the receptors in your brains. Caffeine replaces adenosine, and doesnâ€™t come with the sleepiness effect. You are now awake. Yay!
Iâ€™ll Have Another
As you become a longtime imbiber of caffeine your brain creates more adenosine receptors, and more caffeine is needed to elicit the same response. When you donâ€™t continue to drink caffeine you start to feel withdrawal symptoms and become more tired.
Coffee = Happiness
Caffeine also stimulates adrenaline, which is the fight or flight hormone. In turn, your dopamine levels increase, which is that awesome feeling where you love life and everything is sunshine and rainbows. Your brain on coffee equals happiness, which is the best thing ever.
Making A Fresh Pot
Caffeine has a shelf life of about six hours, so at this time your intake is cut in half, and cut in half again after another six hours. Which is why you may be running around the office at 3 pm asking all of your coworkers to go on a coffee run to Starbucks. See? Itâ€™s science.