Not All Naps Are Created Equal

     According to preliminary data from the 2013 South Kent School Sleep Study, the right nap in the middle of the day serves many cognitive and health benefits. Evidence from recent studies on the topic also shows that the opposite is true. Not only can brief sleep episode of non-REM sleep help improve memory, alertness, and decision making, but excessive prolonged napping can result in drowsiness, memory loss, and other cognitive impairments (Tucker, 2006). 

A graph showing that those 15 students (in red) who regularly nap for a period of 25- 60 minutes wake up refreshed from their nap, while those with longer naps report fatigue and signs of sleep inertia. 

   At South Kent, many of the students' naps  tend to exceed the recommended 25-45 "power nap" minutes, and last over an hour. Typically, when a student wakes up from a 90+ minute nap, he will likely experience sleep inertia-- grogginess, disorientation, confusion and fatigue. These symptoms are characteristic of just having experienced slow moving delta waves of stage 3, stage 4, and eventually faster waves of REM sleep (rapid eye movement), during which dreaming takes place. 

     The South Kent psychology class has collected wide range of "sleep" data from majority of students on campus. Students' naps in particular were a major focus of the study as many students take regular naps during the academic week. As we predicted, although well intended, some of these mid-day naps do not seem to serve their purpose of rejuvenation. 

     If a student taking a nap enters stage 3 and stage 4 of deep sleep, he probably did not experience enough, or adequate stage 3 and 4 sleep during the previous night. Having several nights of insufficient deep sleep with REM cycles, the student's body will accumulate a sleep debt. This sleep debt will make itself known the next day, as the the student dozes off in class or fights to stay awake throughout the day. Finally, when nap time comes, the body will compensate for last night’s lack of deep sleep and REM by entering the very stages of deep sleep during the nap, waking up some 90 minutes later relatively tired. 

How to take a healthy "power nap"

- A good nap should be approximately 25-45 minutes.
- You should feel refreshed upon waking up from 25-45 minute nap.
- You typically should not dream during a 25-45 minutes nap.
- You should only be in stage 1 & 2 (fast moving Alpha Waves).