Caffeine is a chemical substance that influences your sleep. So if you love coffee, as we do, here is how you can have your coffee and sleep it too.
The science
After you wake up, a chemical called Adenosine (which makes you sleepy) starts building up in your body. There are receptors in your brain that receives these chemicals, and they tell us when we should sleep. Imagine an elephant’s trunk taking in apples , and once it eats enough apples, the elephant goes to sleep. Caffeine, as you know is in your coffee, is like a huge plastic cube that forcibly sticks itself onto the elephant’s trunk (receptor), making the elephant (you) unable to take in apples (adenosine).
As time goes on, there is a huge mass of apples on the ground. After some time, the elephant manages to shake off the plastic cube, and starts eating the apples greedily all at one go. There comes the crash; a huge wave of sleepiness with the weight of a whale knocking you out. This is called the Caffeine Crash.
Caffeine’s half-life or effective time
Caffeine has a half-life of about 8 hours, which means half that morning cup of coffee at 7AM stays in your body at 3PM. If you find it hard to sleep at night, it is likely because there is still too much caffeine in your system, effectively blocking your body’s ability to receive the sleepy chemical Adenosine. You are tired, but your brain still doesn’t know it yet, as an army of caffeine is stopping the flood of adenosine from kicking in. By the way, caffeine is digested by your liver, and it is a slow process.
How coffee drinkers can still sleep well
As you now know, each cup of coffee brings in a flood of caffeine that will block the receptors in your brain from receiving adenosine. Therefore, you should have a maximum of 2 cups of coffee per day, especially if the next day is a work day. You know you need to be well-rested for a full day of chores.
Given that the half-life of caffeine is roughly 8 hours, and normal Singaporean sleep time being 10-11PM, we recommend you drink no coffee after 2PM. Remember half the cup of coffee is still in your system at 10PM, making it harder to sleep, especially if you don’t move around much or take in much sunlight.
Depending on your health, weight, metabolism and work, we have found that it is perfectly alright to have a morning cup of coffee and another cup at lunch, and still be able to sleep soundly at bed time. You can have your coffee (in moderation) and good sleep too.
