Caffeine and snoozing have something in common: both make you feel awake and can enhance your performance, whether you’re driving, working or studying.
But some people are absolutely convinced that drinking coffee before a nap gives you an extra boost of energy when you wake up.
How is that possible? Is there any evidence to support the power of these so-called afternoon coffee naps? Or are we better off with just getting a good night’s sleep?
If you don’t get enough sleep, you may suffer from what scientists call a ‘sleep debt’.
You can easily build up a sleep debt without even realising it.
Taking a short nap is a very common way of overcoming your sleepiness and cancelling your sleep debt.
A cup of coffee can also help us get through our day. Since the 1980s, researchers have been studying how coffee and sleep combined might help.
In a 1998 study, 12 people who hadn’t slept properly drank the equivalent of one large cup of freshly brewed coffee and just five minutes later had the chance to snooze for 15 minutes.
They then did some standard driving tests in an electronic simulator to check their alertness.
A coffee nap even improved performance if people just dozed during their nap time rather than falling into a deep sleep, a study previously found.
Although drinking a cup of coffee (without a nap) helped their driving performance, a combination of caffeine with a coffee nap improved it even further.
People who took a coffee nap were less likely to drift out of their lanes on a two-hour monotonous simulated drive.
This was compared to when they had just drunk a coffee (and had no nap) or when they drank a decaffeinated coffee without a nap.
A coffee nap even helped performance if people only dozed during their nap time rather than falling into a deeper sleep.
However, this study has raised many questions.
HOW DO COFFEE NAPS WORK?
To understand why a coffee nap might work, we need to examine how the body processes caffeine. When you drink strong tea or coffee, the caffeine stays in the stomach for quite some time before moving to the small intestine.