The groggy, fuzzy-headed feeling that you experience in the first minutes after coming out of sleep? That sense of not knowing precisely where you are, what time it is or even what day it is? This disorienting, sluggish state actually has a name, and it’s something other than hrmphrgmh. In medical and scientific circles, it’s known as sleep inertia.

Sleep inertia can happen first thing in the morning. It can also happen after waking from a nap. For as long as sleep inertia lasts—usually no more than 30 minutes or so—your brain is actually a little bit impaired. You might feel unfocused (where did I leave my phone again?). You might experience some disorientation (tripping over that same toy, again).


Would you rather chew your caffeine?

As you likely know from experience, the sluggishness that comes with leaving sleep behind tends to be worse if you’re already sleep deprived. If I’m carrying around cobwebs in my brain in the morning, I like to get a quick burst of exercise—sometimes even when I’m still in my pajamas. (A minute or two of jumping jacks in the living room does the trick.) Many of us shake off sleep inertia with a hot shower, or a cup of coffee.

Sleep inertia is different from daytime fatigue or tiredness—though plenty of people experience those on a regular basis as well. It’s safe to say that more people than ever are short on sleep, and feeling the effects of their sleeplessness in a number of ways different throughout the day.

If caffeine is your pick-me-up of choice, then you know there’s no shortage of products available to deliver a caffeinated boost. And it’s not just energy drinks and sodas anymore—these days, you can find everything from water to cookies to popcorn to ice cream with caffeine added to the mix.

Caffeine gum is another one —and there’s some scientific research that suggests it might be helpful in shaking off sleep inertia. Scientists working with the U.S. Navy did some testing of caffeinated gum as a way to relieve post-sleep grogginess. They found chewing the gum immediately after waking may help do away with sleep inertia and improve reaction time.

The U.S. military has actually been using caffeine gum for several years to help improve soldiers’ performance and alertness. The military has done research showing that the controlled amounts of caffeine used in their caffeine gum can help soldiers perform better at their jobs—with things like alertness and focus, and marksmanship skills—and may even reduce their risks of being injured.

Does caffeine gum work better than a cup of coffee at perking us up? Caffeine in gum form is absorbed to the bloodstream—and reaches the brain—more quickly than by drinking coffee or other caffeinated beverages. As a result, its stimulating effects can kick in faster. It’s not hard to understand why the military might use caffeine gum. It’s small, easily portable, quick to consume—the kind of thing that soldiers could carry with them and use in all sorts of circumstances.

So, should you ditch your morning mug of coffee for a square of caffeinated gum? Not so fast. The scientists who performed the study say their results are most relevant to the use of caffeine gum in special circumstances, such as for the military or emergency personnel. For the rest of us, making good nightly sleep a priority is still the best way to combat daytime fatigue. When I’m looking for a little boost of energy in the daytime, I’ll be sticking with a cup of tea—and maybe another round of jumping jacks.