Drinking coffee just before taking a nap seems counter intuitive, stupid even — either rejuvenate naturally by catching up on some sleep, or artificially by slamming the extracted properties of coffee plant seeds.

But coffee and napping are not mutually exclusive activities; in fact, science says when taken together, they can wash away drowsiness more effectively together than separately.

Related: You Could Probably Stand to Nap More, Says Science

Essentially, the time it takes for caffeine to take effect in the body — about 15-30 minutes — is the same time a short nap might take to break down a chemical produced by the brain that causes fatigue, TestTube explains. When we sleep, our brains clear out a chemical called adenosine, which builds up throughout the day. Since caffeine is chemically similar to adenosine and plays off of the same receptors in the brain, the former has a better chance of having a stronger effect as the latter clears out during a short nap.

After 15 to 30 minutes of snoozing, the napper should theoretically wake up just as the caffeine is kicking in, feeling more alert and productive.

Related: 5 Scientific Reasons Why You Need a Vacation

It should be noted, as Vox did, that scientists haven't necessarily observed brains during a coffee nap. Rather, their benefits are based on understandings of how the two chemicals affect the brain separately. But research monitoring subjects who took coffee naps showed better attentiveness on the road and even better memory retention.

For a helpful visual, check out Vox's video on the science behind coffee naps.