Are you drinking early morning coffee to wake you up? Of course you are (we all do). Let’s dig into the science and find out why coffee gets us up and at ‘em!
Beep beep, beep beep… why does coffee wake us up?
Right. We’re going to get a bit sciencey and discover the story behind your coffee wake up.
You might think caffeine would be our first port of call, but we’re going to start by introducing you to a snoozy compound called adenosine. We find this organic compound in our brains, where it connects to receptors and decreases the rate of nerve cell activity. It specifically slows down the neurons found in the basal forebrain (the dozy dudes that make us feel tired). The cells fire less often and the blood vessels dilate, bringing on that sense of sleepiness. Bed is beckoning…
Caffeine molecules look pretty similar to adenosine ones. So similar, in fact, that they can bond with the brain receptors instead of the adenosine. Unlike adenosine, the caffeine molecules don’t slow down the nerve cell activity. They do the opposite – your neurons get a boost. The result? Coffee lover, drowsiness is deterred!
I feel awesome! Why does coffee give us energy?
So, you’re awake (good morning, sunshine). But you’re not just awake; that morning coffee has left you feeling awesome! Why is this? Why does that wake up coffee give us a big boost of energy?
Once our brain senses the increased neuron activity, it tells the pituitary gland to shake into action and release some epinephrine. This is more widely known as adrenaline, or the fight or flight hormone. This makes our heart beat a little faster, helps us to transfer more blood to our muscles and causes our pupils to dilate. Only a smidgen, though: you won’t end up with Betty Boop-sized eyes. Your liver also releases sugar into your bloodstream to make those muscles ready for action!
Does coffee wake you up? Yup, and it gives you an awesome energy boost in the process!
How long does it take for coffee to kick in?
A coffee wake up varies from person to person, depending on how quickly their body metabolises the caffeine. On average, it takes between 15 and 45 minutes for you to feel the effects of your cup. Most people feel perkier after about 15 minutes. The caffeine will peak after about an hour and will stay at the same level for a few hours more, keeping you up and at ‘em as you start work. Yeeehaw!
How long does caffeine last?
Your early morning coffee kick won’t last forever. Sorry. After the spike, your liver quickly begins to metabolise the caffeine. Wait around six hours (5.7, the experts think), and your body will have metabolised about half of the caffeine in your cup. In other words, caffeine has a half-life of six hours.
What does this mean for your wake up cup? Sip a cup of filter coffee, which contains approximately 140mg of caffeine, and 70mg will have left your body by lunchtime (if you brew your first cup around 7ish). Wait ten hours, and all the caffeine will have left your bloodstream, so you’ll still be nice and sleepy by bedtime.
Why does coffee NOT keep me awake?
Brewing that am cup but still not feeling snoozy? We’ve sussed out a few reasons why this might be…
Caffeine tolerance (religiously drinking morning coffee? You might have built up a tolerance)
Your age (younger people generally have speedier metabolisms and so process the caffeine faster)
Your hydration level (feeling thirsty before your joe? Then you might start to feel thirstier after your coffee and struggle to get energised)
Your DNA (the CYP1A2 gene needs to be present and correct in the liver for it to be able to metabolise caffeine. Some people simply don’t have this gene, or might have a defective one)
How much coffee can I drink?
We love caffeine. It’s a good egg. Consume in moderation and you’ll be:
Helping to prevent heart disease, cancer and stroke
In general, we should limit our coffee habit to 400mg of caffeine per day. This is roughly the same as four cups of brewed coffee. It does depend on the type of drink, however. An espresso has somewhere between 60-100mg of caffeine, while a cup of tea gives you just under 50mg.
Meet the chimp behind this article!
Head Chimp founded Two Chimps alongside Laura in 2016 after being self-employed from the age of 21. He caught the coffee bug from using an at-home roaster, and the rest is history!
What Andy does outside of the treehouse:
When the weather’s nice, Andy loves going on bike rides with his trusty sidekick, microchimp Felix (who always leads the way, of course). Andy also enjoys spending time tending to the family’s vegetable garden, and looking after their at-home farmyard, which includes a cat, two guinea pigs, and six chickens!
Andy says…
“I believe every day is a school day, and I’m always looking for opportunities to stick my head in a book and absorb new knowledge. I also love a problem to solve and fix – there’s no such thing as problems, only solutions.”
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