Many of us want (or should I say need?) our morning coffee to give us our “get up and go”. In total, people around the world drink more than two billion cups of coffee every day. (opens in a new tab).
You might think coffee gives you the energy you need to get through the morning or the day, but coffee might not give you as much as you think.
The main stimulant in coffee is caffeine. And caffeine’s main mode of action is to change the way our brain cells interact with a compound called adenosine. (opens in a new tab).
to be busy, to be tired
Adenosine is part of the system (opens in a new tab) which regulates our sleep-wake cycle and partly explains why high levels of activity lead to fatigue. As we go about our days and activities, levels of adenosine increase (opens in a new tab) because it is released as a by-product when energy is used in our cells.
Eventually, adenosine binds to its receptor (opens in a new tab) (parts of cells that receive signals) that tells cells to slow down, making us sleepy and sleepy. That’s why you feel tired after a big day of activity. While we sleep, energy consumption decreases (opens in a new tab) by lowering levels of adenosine as it is reintroduced into other forms. You wake up in the morning feeling refreshed. Well, if you get enough sleep, you do.
If you still feel sleepy when you wake up, caffeine can help you for a while. It works by binding to the adenosine receptor (opens in a new tab), which it can do because it is a similar shape. But it’s not so similar that it triggers the sleepy slowdown signal like adenosine does. Instead, it just fills in the spots and prevents adenosine from binding to them. This is what avoids the feeling of drowsiness.
Laurits Regner Tuxen, Danish artist, 18531927. Serving morning coffee, 1906. pic.twitter.com/PwftbbSyaQJanuary 22, 2023
No free ride
But there is a catch. While energizing, this little caffeine intervention is more of a borrowing from the feeling of awake than a creation of whole new energy.
That’s because caffeine won’t bind forever. (opens in a new tab), and the adenosine it blocks does not disappear. So eventually the caffeine breaks down, lets go of the receptors and all that adenosine that’s been waiting and building up, and the feeling of sleepiness returns – sometimes all at once.
So the caffeine debt you owe still has to be paid off, and the only real way to pay it off is to sleep.
Timing is everything
The amount of free adenosine in your system that hasn’t yet attached to receptors, and how drowsy you are as a result, will impact how much caffeine you drink to wake up. So the coffee you drink later in the day (opens in a new tab)when you have more drowsy signals, your system may seem more powerful.
If it’s too late in the day, caffeine can make it hard to fall asleep at bedtime. Caffeine’s “half-life” (the time it takes to break down half of it) is about five hours (opens in a new tab). That said, we all metabolize caffeine (opens in a new tab) differently, so for some of us the effects wear off faster. Regular coffee drinkers may feel less caffeine “punch” with tolerance (opens in a new tab) to the stimulant that builds up over time.
Caffeine can also increase cortisol levels (opens in a new tab), a stress hormone that can make you more alert. This could mean the caffeine feels more effective later in the morning because you already have a natural cortisol rise when you wake up. The impact of a coffee out of bed may not seem so powerful for this reason.
If the caffeinated beverage of your choice is also sugary, it can exacerbate the peak and crash feeling. Because while sugar creates real energy in the body, the free sugars in your drink can cause your blood sugar levels to spike, which can then tire you out when the drop comes after. (opens in a new tab).
Although there is no proven harm in drinking coffee on an empty stomach, coffee with or after a meal (opens in a new tab) might hit you slower. This is because food can slow down the rate at which caffeine is absorbed.
Read more: Does coffee burn more fat during exercise? What the evidence tells us (opens in a new tab)
How about a strong tea or a sparkling cola?
Coffee, of course, isn’t the only caffeinated drink that can give you energy.
The caffeine in tea, energy drinks and other beverages still has the same impact on the body. But, since the ingredients come primarily from plants, each caffeinated drink has its own profile of additional compounds that can have their own stimulating effect. (opens in a new tab)or may interact with caffeine to alter its effects.
Caffeine can help, but it’s not magic. To create energy and re-energize our bodies, we need enough food, water and sleep.
This article is republished from The conversation (opens in a new tab) under Creative Commons license. Read it original article (opens in a new tab).