How Caffeine Impacts Your Energy Cycles

How Caffeine Impacts Your Energy Cycles

The Highs and Lows of the Caffeine Energy Roller Coaster 

Have you ever wondered why caffeine makes us feel alert in the short term but can lead to a crash in the afternoon, interrupted sleep, and a sluggish feeling the next morning? The highs and lows associated with drinking caffeine is something we like to call the “Caffeine Energy Roller Coaster.” To understand this cycle, we must first look at what is going on inside our brain that gives us energy and makes us feel sleepy.

Our Energy Levels Revolve around the Adenosine Molecule

Throughout the day, adenosine molecules build up in our bodies as a byproduct of burning energy. These Adenosine molecules bind to specific receptors in our brains that tell us we need to rest. As more Adenosine binds to Adenosine receptors, we begin to feel sleepy and drowsy. During sleep, the brain replenishes its energy reserves and begins to eliminate Adenosine. Eventually you wake up when there are very low levels of Adenosine in the brain. 

Now that we have had a brief understanding of how adenosine impacts energy, let’s take a deeper look into how caffeine interrupts this energy cycle and how it makes us feel at different times throughout the day.

Caffeine Competes with Adenosine 

The structure of adenosine and caffeine are very similar, which means that caffeine can also bind to adenosine receptors.


Image by: Chemistry Help

When caffeine is bound to the receptors, it blocks adenosine, preventing it from telling your brain that you need to rest. This is how caffeine makes you feel more alert, not by giving you energy, but by temporarily blocking your naturally increasing tiredness. 

For an interesting detailed diagram, check out this article by Integrative Pharmacology.

Early Morning: Daily Caffeine Withdrawal

“Don’t talk to me until I’ve had my coffee.” Sound familiar? Chronic caffeine users can experience daily caffeine withdrawal symptoms in the early morning before they have their usual dose of caffeine. 

Our founder, Kait, just assumed she wasn’t a morning person because she couldn’t remember ever waking up and feeling awesome. She was shocked to later find out she was experiencing caffeine withdrawal every single morning.

Over time, our bodies become dependent on caffeine and we experience withdrawal when we have gone a long time without it. If your last cup of caffeine was at 2pm, that’s 18 hours between your PM and next AM cup.

Late Morning: Caffeine-Fueled Alertness

Whenever you start your day with a caffeinated drink like coffee you begin to feel more alert. Why? Not because it gives you energy, but because it temporarily hides any tiredness you are naturally feeling. You may feel wide awake, focused and at the top of your game after you’ve had your morning caffeine. Unfortunately, this is temporary.  

Afternoon: Caffeine Crash

By the afternoon your body has broken down some of the caffeine you consumed in your morning coffee, leaving those adenosine receptors empty and available. Since adenosine has built up throughout the day, these open receptors are suddenly bombarded by adenosine molecules causing sleepiness fairly quickly, aka, the afternoon crash. We’ve all been there where we’ve tried to struggle through it, but often give in to another cup of coffee.

Evening : Why can’t I sleep?

At this point in the day, you may be ready to wind down, but your brain is not. Since the half-life of caffeine is about 6 hours, its stimulating effects may still be at work well into the evening. If you drink a cup of caffeinated coffee at 2pm, you have half of that amount in your system at around 8pm. Now it’s a waiting game for your body to break down enough of the caffeine in your system to free up adenosine receptors and trigger your body to sleep.

Your Body Needs More Caffeine to Get the Same Effect

If you consume caffeine on a daily basis, you likely started with one cup a day and have increased that number of cups over time to combat the afternoon crash and make yourself feel better. Many of our beloved social rituals also revolve around coffee, so it isn’t surprising how much caffeine many of us drink each day! Over time, your caffeine tolerance increases and you need more caffeine to feel the same. This may be due to your body creating more adenosine receptors to compensate for the receptors blocked by caffeine. 

Essentially you are fighting against your body. You drink caffeine which blocks adenosine receptors. Your body needs available adenosine receptors to function normally, so it creates more. Then you feel sleepy, drowsy or other types of awful and drink more caffeine to overcome those feelings. Then your body creates more receptors. 

But there is hope

When you first give up caffeine, you may feel extended withdrawal symptoms like you do in the morning. If you have developed a dependence on caffeine, withdrawal symptoms may include headaches, difficulty concentrating, nausea, tiredness, and irritability.

These symptoms can last up to a week until the number of adenosine receptors return to normal. The best way to minimize withdrawal symptoms is by slowing weaning yourself off of caffeine.  See our Caffeine Step Down Plan for a guide to reducing your caffeine at your own pace.

Getting off of the Caffeine Energy Roller Coaster

Now that you understand how caffeine affects your body’s natural energy cycles,  you may see why many people who significantly reduce caffeine report more balanced natural energy levels throughout the day once they’ve left the Caffeine Energy Roller Coaster behind

If you’re tired of being on the Caffeine Energy Roller Coaster and you can’t imagine giving up the taste, warmth and ritual of coffee, check out Savorista’s astonishingly delicious decaf and half caf coffees.