Why does caffeine work?

Have you ever thought about it? You drink coffee or tea and your brain wakes up. What is going on in there to make that happen?


Let’s break it down, starting with why you are feeling tired. From the moment you wake up in the morning, your brain is accumulating a chemical called adenosine. Think of this as a chemical barometer, helping your brain to measure how long it’s been awake. This is part of your natural sleep wake cycle, it’s one of the things that makes you fall asleep at night and wake up in the morning.

The adenosine is building up in your brain, and your brain can tell how much is in there because it has special receptors just for this purpose. What the caffeine does is grab onto those same receptors and block your body’s ability to tell how much go back to sleep chemical is present.

One second your brain is bogged down by receptors measuring sleepy levels of adenosine, the next second caffeine has grabbed on and tricked your brain into thinking that it’s wide awake, first thing in the morning! Great, right?

There are definitely some drawbacks to caffeine, the biggest one being the crash. What causes that? Well, even though caffeine is blocking the receptors, adenosine is still building up in your brain at the same rate it always is. That means that when the caffeine lets go, your adenosine levels will be a lot higher than they were when it grabbed hold, and it hits you all at once because you didn’t get the feeling of it building slowly over time. That’s zero to tired in about 2 seconds!

Now that you know all of this, you are probably asking yourself why you crave coffee first thing in the morning, right? Shouldn’t your adenosine levels be so low that you wouldn’t even think about it? There are 2 reasons for this. First, your brain deals with the day’s built up adenosine when you are asleep. If you failed to get your 7-9 hours, or were under the influence of something during those 7-9 hours, chances are you will wake up with some of the chemical still in your brain. The other reason? Caffeine is a very addictive drug. You are craving it the same way you would crave any other drug that were were addicted to.

How to conquer the need for coffee first thing? Start by getting enough sleep. Good, solid, sober sleep. Then cut back on your caffeine slowly over time. Lots of people have success with tapering off to decaf bit by bit. Or switching to lower caffeine tea. It seems counter intuitive, but you will have more energy in the long run if you ditch caffeine altogether. Want to know what gives me energy? Getting 8 hours of sleep and drinking lemon water in the morning, followed by a cup of decaf. Sound dorky? Give it a try for a week. You will change your tune halfway through shift when you are still feeling great and kicking ass.

Laura Mcwilliams