We’ve all been there — that moment when our eyes droop during lecture, or we go for our third cup of coffee to make it through afternoon clinic. Through dental school, I’ve gone through various phases of trying to stay awake, but at the start of my fourth year, ahead of NBDE Part 2 and ADEX, I needed to refresh my tactics. I polled my friends on how they coped with exhaustion and found two decidedly different camps: one entirely dependent on caffeine and the other who swear by the power of naps. I decided to investigate both in hopes of nailing down the perfect routine.
Caffeine is a huge part of my life and is honestly up there with the top few loves of my life. How does this nifty chemical play such a huge role in my happiness? In short, it comes down to adenosine. Yep, that same adenosine from our NBDE Part 1 preparations. Biologically, adenosine, a natural byproduct of our body, functions to protect us from energy depletion. When extracellular adenosine levels rise, the corresponding neuronal receptors get saturated, causing a decrease in neuronal activity and the induction of sleepiness. According to the Caffeine and Adenosine review article in the 2010 Journal of Alzheimer’s Disease, caffeine is an antagonist of the adenosine receptor, fitting into those same spots to prevent us from feeling tired.
While the mechanism of caffeine is standard, the type of caffeine used is a personal choice. According to the Center for Science in the Public Interest, coffee has the most bang for your buck with roughly 100mg of caffeine per 12-ounce cup, while black tea drops to 60mg, and soda is limited to 71mg per can by the FDA (minus the energy boost from all the sugar). What you choose is up to you, but the FDA recommends no more than 400mg of caffeine (or roughly four cups of caffeinated coffee) a day.
I’ve never been a consistent napper. Sure, I’ve accidentally passed out while attempting to study, but the ritual of setting an alarm for an afternoon nap has always seemed to require too much planning for me, which means that my “I’ll shut my eyes for just a moment” breaks inevitably turn into hour-long naps that leave me feeling more tired than before. It turns out I’ve been doing it all wrong!
When I sleep for long periods of time, allowing my body to fall into what’s known as deep sleep, experimental studies show a phenomenon called “sleep inertia,” where cognitive ability can actually be temporarily reduced. The shorter the nap, the better. A 2001 study published in Sleep showed that a 10-minute nap yielded a higher increase in alertness and cognitive performance than a 30-minute nap. But it seems that the real key is a combination of both, sometimes referred to as a “coffee nap.” A coffee nap is simple: You drink coffee (ideally as quickly as possible), and you immediately take a short nap. The caffeine in coffee doesn’t take full effect until roughly 30 minutes after drinking it, so a 10- to 20-minute nap is just enough time to get you refreshed.
In a 1997 study on suppression of sleepiness in drivers, it was found that combining the caffeine found in roughly two cups with a short nap was shown to increase subjective alertness in driving simulators. A Clinical Neurophysiology study found that coffee naps led to better memory test results than dozing off alone. While we know caffeine acts as an adenosine receptor antagonist, it has both low affinity and low specificity, failing to fill every single adenosine receptor. Since sleeping removes all the excess adenosine from the brain, combining caffeine with sleep can allow your brain to fire on all cylinders.
Interestingly, strategies to stay awake can vary in success by age. In a 2007 article in Sleep, drinking caffeinated coffee helped reduce driving risk by almost 90 percent in middle-aged drivers while taking a nap reduced risk by 23 percent. The same study found no significant difference in the risk reduction of drivers in their 20s. This reinforces that everyone is different and that no one method works best. While I haven’t personally tried the coffee and nap combination, it does seem like a promising way to get through not only boards but the long hours of dental school as well.
~Aria Sharma, Florida ’19, District 5 Cabinet