Coffee gives you some energy and cheats the system while in the process of it. Caffeine competes with the calming chemicals in your brain, and it wins, keeping the sleep at bay.
How coffee keeps you alert?
Apparently, there’s chemical in your brain called adenosine that slowly accumulates in the brain when you wake up, and it binds to receptors which slow down your brain’s activity. Ultimately, the more adenosine in your brain the more fatigued you become.
Conversely, while you sleep, the concentration of adenosine declines gradually promoting alertness.
But it turns out that the caffeine in your coffee is incredibly similar to adenosine in structure. The caffeine works its way through your bloodstream and into your brain where it starts to compete and binds to the adenosine receptors.
But because it’s not adenosine the sleepiness effect isn’t felt. Adenosine can no longer bind, meaning its calming properties are diminished which is great for you when you’re feeling tired.
Excess coffee intake triggers your constant fatigue
Long-term use of caffeine makes your brain responds by creating more adenosine receptors, which means more caffeine is required to elicit the same response of keeping alert.
It also means that when you try to quit drinking coffee or miss your daily intake, you might experience some withdrawal symptoms and feel more tired than you would have before you ever drank coffee.
But the caffeine doesn’t stop there.
It also stimulates the production of adrenaline, you know – the fight or flight hormone. This increases your heart rate gets your blood pumping and even opens up your airways.
Furthermore, it affects dopamine levels. Dopamine is the feel-good hormone. Caffeine prevents its re-absorption in the brain.
In fact, this is the exact same thing that cocaine does just to a lesser degree. It’s a drug after all. This dopamine stimulation is also the aspect of coffee that makes it moderately addictive.
Lethal Limit of Caffeine
So can you drink too much coffee? It turns out there is a lethal dose of caffeine, which is somewhere around 150 milligrams of caffeine per kilogram of your body. This means if you weigh 70 kilograms you would require 14,000 milligrams of caffeine to overdose.
Put into perspective, an average cup of coffee contains roughly 150 milligrams of caffeine meaning if you’re 70 kilograms approximately 70 cups of coffee would kill you. However, you’d have to drink those cups all at once making it effectively impossible to overdose on caffeine from coffee since you wouldn’t be able to physically fit that much in your stomach. You would also start experiencing mania and hallucinations before getting to this point.
Don’t use the lethal limit to justify continual intake, too much coffee is not good for you.
Caffeine also has a half-life of around six hours. So if you drank a standard coffee with around 150 milligrams of caffeine, after about six hours you’ll have 75 milligrams left in your system.
At that point you’re feeling half of the effect. And after another six hours, you’ll have 37.5 milligrams, leaving more room for adenosine to jump back into action. That’s the point you reach for another cup of coffee.
So drink up and enjoy the buzz while it lasts. But remember that drinking caffeine means not drinking something else…like water, juice, smoothies, and other good options!
