I “Quant” Believe I’m Monitoring My Sleep, and It’s Working

One unanticipated consequence of upgrading to an Apple Watch Series 3 is that I’ve been monitoring my sleep. That’s right: I am the same data grouch who bemoaned the quantified life, and here I am, tracking the amount of time I sleep, measuring the “quality” of my sleep, and comparing my sleeping heart rate from one day to the next. What’s wrong with me?!?

Part of this new regiment started when I upgraded to a new Apple Watch. The Series 3 offers a much improved battery compared to my old Series 0. However, I also started monitoring my sleep because, a year ago, I had downloaded a sleep-tracking app called Auto Sleep. The app wasn’t useful on my Series 0 because the battery would die in the middle of the night, and ironically, the watch itself would wake me up when I would toss and turn in bed. There were several occasions where the watch strap or the chassis itself would rub against my face, interrupt my sleep.

I was also curious of whether my sleeping habits were in need of some help. Like most people, it is not unusual for me to become tired in the middle of the day. Fortunately, my working conditions allow me to often remedy that with a quick coffee nap. I think that’s the only part of owning a car I miss: lunchtime naps in the parking lot.

Although I have had the speedy Series 3 with its capacious battery for over a month, I’ve only regularly started tracking my sleep over the last few weeks. Here’s what I’ve learned:

The first thing that I noticed that I don’t get anywhere nearly as much sleep as I thought I did. I discovered that I spend about an hour in bed awake each night, oftentimes much more than that. Prior to this sleep-tracking experiment, I would reason that if I go to bed around midnight and wake up about 7:00, I got a respectable seven hours of sleep. Wrong! The Auto Sleep app reports that I get closer to five hours of sleep on such nights. This is because I wake up multiple times in the middle of night: a bathroom break here, a neighbor or roommate making a sharp noise, a pesky cat asking for a predawn snack. The time I lie awake in bed likely explains why I get drowsy in the middle of the day.

Since then, I started to budget over eight hours in bed to get a respectable amount of sleep—about seven hours—each night. I can now appreciate the wisdom of Max Richter’s Sleep album, a collection of 204 songs that together last 8 hours and 23 minutes. The notes guarantee eight hours of sleep, and clearly count on some degree of sleeplessness during that stretch. I tried it but, as I tossed and turned, I kept bumping into my iPad that I had foolishly propped on a pillow next to my head.

A second discovery I made was that my average heart rate while sleeping is noticeably affected by two factors: whether I’ve been getting enough restful sleep over the past several days and whether I drank even a moderate amount of alcohol.

Observing the first factor was a revelation. I saw my sleeping heart rate drop from as high 78 bpm at the beginning of a restful-night streak to something in the low 60s.

However, last Wednesday, March 21, during what appears to have been the final Nor’easter of March 2018, I walked to the local brewery to stave off cabin fever and to taste some new IPAs. I nursed four pints over a four-hour period, but that was enough to wreck my sleep. Auto Sleep rated that night’s sleep with a 58% recharge rating, whereas I had scored something closer to 90% over the past three days. My average heart rate on that stormy, intemperate night was 79 bpm, which is similar to my heart rate while I sit at this desk and type, whereas my heart rate was 12-13 beats slower during the previous three nights. Finally, it had a lingering effect over the next two nights: my recharge rating was closer to 80%. It wouldn’t be until two more nights that I again scored a recharge rating of at least 90%.

The effects of nursing four pints of IPA over four hours on my sleep were pretty hard and lingered for a couple of days.

A third revelation from this whole sleep-monitoring exercise is that I have to work harder to get enough sleep. That defies my own sense of logic. But working hard to sleep more is something I can get behind.

Finally, I have been noticing an overall positive effect on my energy. I haven’t needed my customary coffee nap after getting a few consecutive nights of quality sleep. I don’t know if it’s a placebo effect, but just the other day, I tried to take a quick lunchtime nap. I couldn’t do it. I was wide awake, and instead, I started composing a draft for this post.

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