We’ve all been there. You’ve just eaten lunch and you’re getting back to work, but you can feel your energy and focus fading. You need a nap or more caffeine to get you through the afternoon. But have you considered both?
Conventional wisdom says that caffeine and sleep don’t mix. However, studies show that taking a quick nap right after drinking a caffeinated beverage actually improves your alertness and cognitive function more than a nap or caffeine alone.
So how does it work?
To understand how caffeine naps work, you first need to understand the effect caffeine has on your body.
When you consume caffeine, it’s absorbed in your small intestine and travels through your bloodstream to your brain. Once there, caffeine fits into a certain type of neuroreceptor that is normally filled by a molecule called adenosine.
Adenosine is a natural byproduct of normal brain activity. As it accumulates, it starts plugging itself into receptors in your brain, which tells your brain to feel tired. Basically, adenosine is the enemy when it comes to staying awake and alert.
When caffeine bonds to the adenosine receptors, it blocks the adenosine from taking hold. As Stephen R. Braun, author of Buzz: The Science and Lore of Alcohol and Caffeine puts it, it’s like “putting a block of wood under one of the brain’s primary brake pedals.” However, the caffeine doesn’t block every single adenosine molecule. The two compete for receptors, meaning some adenosine still gets through. That’s where caffeine naps come in!
Sleeping naturally clears adenosine from your brain, leaving more receptors free for the caffeine to take hold.
Experiments on the Effectiveness of Caffeine Naps
Scientists haven’t studied what exactly is going on in the brain during a caffeine nap, but they have conducted several studies on their observable effects. Study after study found that they’re more effective than caffeine or naps alone in counteracting sleepiness and improving the subjects’ performance in various tests.
A study at Loughborough University tested subjects’ driving abilities in a car simulator after giving them caffeine, a caffeine placebo, a 15 minute nap, or a 15 minute caffeine nap. They found that the combination of caffeine and a nap significantly reduced driving impairments and EEG activity indicating drowsiness.
Another study in Japan tested subjects’ sleepiness after taking a caffeine nap, nap only, and no nap, as well as nap plus exposure to a bright light, and nap plus washing their face. They found the caffeine nap most effective for increasing performance, and subjects who took the caffeine nap reported the greatest decrease in their sleepiness.
A third experiment studied the effects of caffeine naps on individuals who were severely sleep deprived. The subjects took a series of performance tests while well-rested, and then were subjected to a 24 hour period of sleep loss. One group of subjects was given a caffeine nap, and then given the performance tests again, and amazingly, their performance was very close to their performance in their fully-rested state.
Sounds pretty good, right? So how do you get these awesome effects?
Coffee Naps versus Tea Naps
Most discussions around caffeine naps focus on coffee. After all, coffee has a greater caffeine content than tea, right? Not necessarily.
A standard cup of coffee contains around 150 mg of caffeine, and a standard cup of black tea contains around 80 mg. However, tea brands such as Zest Tea make teas with a higher caffeine content. A mug of Zest Tea boasts around 155 mg of caffeine, comparable to your average cup of joe.
In fact, drinking tea instead of coffee may even be better for a caffeine nap. Several studies suggest that tea is more effective than coffee in keeping you alert, because it contains l-theanine.
L-theanine is an amino acid found almost exclusively in tea, and it functions in the body very similarly to caffeine. L-theanine is similar in shape to glutamate, a neurotransmitter with excitatory effects on the brain. When l-theanine binds with the receptors designed for glutamate, it produces a calming sensation, while simultaneously improving alertness.
Studies show that consumption of caffeine and l-theanine together cause greater cognitive performance in subjects than either individually, as well as increasing the subjects self-described alertness and decreasing their tiredness. Plus, studies show that l-theanine moderates the effect of caffeine, therefore preventing the caffeine jitters and subsequent crash that many people experience after drinking coffee. So if you need more than a few hours of productivity, tea is your answer!
How to Take a Caffeine Nap
Choose the right time. A caffeine nap evening may rejuvenate your focus, but it may also leave you struggling to sleep that night. Sleep studies show that for the average person, the best time to take a nap without disrupting your sleep schedule is between 2 and 3 pm.
Caffeine can also affect your sleep patterns. In a 2013 study, subjects experienced significant sleep disturbances when they consumed caffeine 6 hours before bedtime. This occurred even when the subjects didn’t perceive any effects from caffeine on their body. For this reason, we recommend cutting off your caffeine consumption in the early afternoon.
Drink your tea. Choose a tea you love with a high caffeine content and enjoy! For best effects, drink your tea quickly, so you have as much time as possible to sleep before the caffeine makes it to your brain. If you prefer not to drink hot tea quickly, you can brew it ahead of time and let it cool down, or try cold brewing it!
Immediately try to sleep. You have a limited amount of time before your caffeine kicks in, so find a nice place to lie down and take your nap. It’s okay if you struggle to fall asleep–just relaxing or reaching a half-asleep state can still be better than no relaxation at all.
- Wake up within 20 minutes. When you nap longer than 20 minutes, you brain is more likely to enter deeper stages of sleep that are harder to wake up from. The grogginess you experience after waking up from a longer nap is called sleep inertia, and is counterproductive to your goal of feeling more awake and alert. Caffeine also takes about 20 minutes to take effect, making a 20 minute nap your sweet spot.
So the next time you’re feeling drowsy in the afternoon, make yourself a nice cup of tea and find a comfy place to lie down. Your body and mind will thank you.