Am I really getting a good night’s sleep?

Sleep! Everyone does it, but what really happens while we drift off into this restful state? I have been pretty skeptical of all the apps out there claiming to “monitor your sleep” by just activating the app on your phone and leaving it on your bedside table. A friend once told me that he turned on an app during the day, left his phone at home, and by the end of the day it miraculously had an analysis of his sleep even though he wasn’t sleeping.

I am more convinced that you can be more accurately monitored while wearing a physical device on yourself while sleeping, and took the plunge to get a Fitbit One (a device that you clip onto yourself to track your health and sleep habits). I tried it out the first time last night, and here’s what I saw on my dashboard the next day:

Capture

I was surprised to see that I had 27 minutes of “awake” time throughout the night. What was going on at 4 a.m. that made me wake up 10 times? Didn’t I sleep right through the whole night? What the hell is sleep efficiency and an awakening anyways? Confused at my diagnosis, I started to try and decrypt it.

The textbook definition of sleep efficiency is actual sleep time/ potential sleep time (so in my case 419 min / 449 min). A “normal” percentage is 85%, and a percentage above 90% considered is “very good”.

Okay, so at least my percentage seems good, but what about waking up 10 times? According to the American Sleep Apnea Foundation, “arousals–interruptions of sleep lasting 3 to 15 seconds–can occur spontaneously or as a result of sleep-disordered breathing or other sleep disorders. Each arousal sends you back to a lighter stage of sleep. If the arousal last more than 15 seconds, it becomes an awakening.” When looking around, many of the sleep institutes and medical sites stated that there isn’t really a “normal” amount of awakening. What is more important is not the number of the awakenings, but the reason behind the awakenings (so Fitbit One is failing me on that analysis), but on one site I saw this:

“It is common and benign for normal sleepers to awaken several times each night.  Generally, normal sleepers briefly awaken at least five or six times between sleep cycles each night, and then fall back asleep within seconds.  Typically these very brief periods of awakening are so short they are forgotten by morning.

Even the best sleepers awaken to some degree at least 10 to 15 times per night and forget about them by morning.  Finer indications of arousal, such as brain wave activity measured in a sleep lab, show that normal sleepers actually awaken some 10 times or more per hour on average, although these arousals typically last less than 15 seconds.  Transient awakenings like these are benign, and by themselves nothing to worry about.”

Who knew that sleep was so complicated? In any case, even though there is still plenty of skepticism on the accuracy of these sleep-monitoring devices, it is still fun to play around with your personalized dashboard and be compare your sleeping and health habits over time.

To see how the Fitbit One works, check out the video below:

http://cache.fitbit.com/media/us/one/assets/video/video.mp4

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