At school and at home, people always tell me how they were tired and just wanted to sleep. Now that the opportunity arises, I would ask what they’ll be up to and one of the replies would always be—get this—sleep. It was as though the only thing on their agenda was to wake up at noon, go to work/school, nap, do work, nap, eat dinner, nap, stay up, and sleep. Even with my lack of knowledge, I know for a fact that this amount of z’s was not healthy. So it got me wondering, how long a nap is too long?

First off, let’s get acquainted with the different kinds of naps: micro-sleep, mini-nap, original power nap, and the lazy man’s nap. 

The micro-sleep are those few seconds of unsuspected dozing off. This quick shut-eye could happen anywhere. According to the AAA Foundation for Traffic Safety, about 16.5% of fatal car accidents are caused by the micro-sleep.

The mini-nap lasts about five to twenty minutes, which increases your awareness, energy, and motor learning and performance.

With the duration of a flat twenty minutes, is the original power nap. It includes the benefits of the mini-nap as well as improvement in muscle memory, clearing the mind, and long term memory.

The lazy man’s nap is around thirty, and if you barely had shuteye last night, lasts until ninety minutes. It improves your emotions, perceptual memory, and creativity. This is the longest a nap should be.

Studies have shown the healthiest nap is the twenty-minute original power nap. This is the nap that helps you wake up alert and hit the ground running. Since it is only twenty minutes, you fall into the lighter stages of non-REM (rapid eye movement) sleep—the dreamless sleep. Any more time, you begin falling into a deeper slumber, slowing down your brain waves. This short amount of time that gets you rested, awake, and ready is what makes the power nap ideal.

Although a nap should not exceed thirty minutes, it is fine to go over if you did not get enough rest. However, not getting the recommended seven to nine hours of sleep and taking a ninety-minute nap will do no good. You will wake up more groggy and tired, possibly suffering from sleep inertia (the inability to do anything after waking up). Oversleeping will also lead to health problems: cardiovascular disease, headaches, diabetes, and cognitive impairment. I’ve always followed my belief that if it lasts longer than an hour, it’s not a nap, it’s sleep.