Sleep tracking can be worthwhile

I find this article from the NY Times annoying. Based on two weeks of using his Apple Watch with only one app monitoring sleep patterns, he’s concluded that he’s discovered a “sad truth” — that it’s a “pointless exercise” to try to track sleep. Altho the article contains quite a bit of useful information about sleep, its importance, and how to get more high quality sleep, he concludes — based on one example — that an Apple Watch and app are pointless in having a better sleep. But no sir.

First, he chose an app other than SleepWatch which I have concluded, with support from other reviewers, is the most helpful. Unlike his choice which offered nothing but raw data, SleepWatch asks questions about why your sleep is different from your normal pattern and uses that as a base for later monitoring. SleepWatch has determined that I sleep best at particular time of the day and has suggested pre-sleep activities to improve the quality of my sleep. In effect, the app I prefer incorporates many of the helpful hints this author had to seek elsewhere.

Second, this author only verified the amount of time he sleeps with the app he used. He didn’t look at the depth of his sleep, whether his sleep was broken up more when he went to bed at different, or his trends over a week of sleep. Given that many people sleep late on weekends, he might have gained from learning whether that approach was good or bad for the quality of amount of sleep. He chose not to look at the details (apparently) because he thought knowing more might make him worry — even tho the purpose of using the Apple Watch with app was precisely to give him information.

If this writer had been sincere about getting the most from this process, he would have used several apps either concurrently or consecutively. He would also have spent a bit of time comparing his subjective opinion — that he sleeps 6-1/2 hours of sleep, end stop — with the data received over a period of time. Given that most of the helpful information is not from his very limited experiment, but from what sleep experts told him (all of it general), I’m simply disappointed that he believes it all to have been pointless. What a shame.

Again, I highly recommend using an Apple Watch with the SleepWatch app for those who are serious about trying to learn about their own sleep habits and how to improve them. I believe you will find it worthwhile.

The Sad Truth About Sleep-Tracking Devices and Apps

Our personal tech columnist tracked his sleep for two weeks with an Apple Watch and some software. Here’s why he concluded it was a pointless exercise.

CreditCreditGlenn Harvey


For the last two weeks, I’ve added an extra step to my bedtime routine: strapping a computer around my wrist.

The new nightly move was prompted by a cascade of wearable gadgets from companies like Fitbit and Apple, which claim that their sensor-laden bracelets and watches can improve our lives by helping us detect health problems so that we can come up with solutions.

For many years, fitness gadgets have measured basic data, like footsteps or calories burned, to motivate us to stay active or shed pounds. Sleep tracking is still a nascent area that tech companies are experimenting with — one that I’ve watched with interest as someone who has been sleep deprived for many years.

In the past, I’ve tried several gadgets with sleep tech, including Fitbit watches and Bose’s sleep-aid earbuds. But I hadn’t consistently tracked my sleep habits and patterns before. Would it really make a difference, I wondered, to have this data? Would it help me to sleep better?

I decided to test it out. I wore an Apple Watch, since it is one of the most popular health-tracking devices. I also downloaded a top-rated app called AutoSleep, which uses the Apple Watch’s sensors to follow my movements and determine when I fell asleep and woke up. (The Apple Watch lacks a built-in sleep tracker.) Here’s what AutoSleep gathered on my sleep habits.

CreditBrian X. Chen
CreditBrian X. Chen

But the excitement ended there. Ultimately, the technology did not help me sleep more. It didn’t reveal anything that I didn’t already know, which is that I average about five and a half hours of slumber a night. And the data did not help me answer what I should do about my particular sleep problems. In fact, I’ve felt grumpier since I started these tests.

That mirrored the conclusions of a recent study from Rush University Medical College and Northwestern University’s Feinberg School of Medicine. Researchers there noticed patients complaining about sleep data collected by apps and devices from Nike, Apple, Fitbit and others.

In their study, the researchers warned that sleep-tracking tech could provide inaccurate data and worsen insomnia by making people obsessed with achieving perfect slumber, a condition they called orthosomnia. It was one of the latest pieces of research supporting the idea that health apps don’t necessarily make people healthier.

“If you look at your data, it can modify the perception of your sleep,” he said. “You may think: ‘Oh, gosh, I didn’t sleep well. Should I be tired? Am I in a bad mood?’”

Here’s what I learned after two weeks of sleep tracking.

To understand sleep-tracking data, I delved into how sleep works. There are three main stages: Light sleep, deep sleep and REM sleep (for rapid eye movement).

The deep sleep stage is beneficial for physical restoration, like muscle reparation and metabolism recovery, researchers said. REM sleep, the stage in which we dream, helps in repairing our psychological and emotional networks.

On average, a person completes a sleep cycle, which includes each of the three main stages, every 90 minutes. To get a good night’s sleep, you need to complete four or five cycles. That’s partly because the cycles are not the same throughout the night: The early cycles have more deep sleep, whereas the later ones have more REM sleep.

But our sleep-tracking tech? It generally can’t accurately measure REM sleep.

In sleep-tracking labs, the gold-standard scientific equipment typically includes sensors that are connected to someone’s face and neck to measure eye and brain activity, among other variables.

But sleep-tracking apps for wearable devices like the Apple Watch or Fitbit primarily look at movement and heart rate to determine when you are asleep or awake — which are generally not precise enough to measure the different sleep stages, Dr. Vallat said. Without a good look at REM sleep, those apps may give an incomplete picture of sleep quality.


Here is where the AutoSleep app gets credit: It estimates sleep duration and deep sleep using the motion and heart rate sensors, but it does not attempt to guess REM sleep. David Walsh, the computer scientist who developed AutoSleep, said he knew the movement and heart rate sensors would not accurately estimate the REM stage, so he didn’t bother.

Another unknown for sleep trackers are the algorithms that are being used to measure people’s sleep, Dr. Vallat said. In contrast, the algorithms used by university sleep labs have been publicly shared for decades.

Some scientists said consumer-grade sleep trackers should not be dismissed as inaccurate. Michael Grandner, director of the University of Arizona’s sleep research program, who has consulted for Fitbit, said that wrist-worn sleep trackers had a long history of use in scientific research and that some devices could be very accurate at measuring sleep stages. He added that the devices enabled some sleep tracking to be done in the real world, not a lab.

O.K., but what happens once you collect your sleep data from a tracker or an app? There is no real answer.

My sleep-tracking statistics said I needed more sleep. (Duh.) Buried deep inside the data was some general information about sleep, but the app stopped short of offering advice on how to solve my personal sleep problems.

Dr. Ethan Weiss, a cardiologist at the University of California, San Francisco, has been wearing a ring on his finger called Oura Ring, which includes a sleep tracker, for nearly a year. The ring measures motion and heart rate to present granular data about the different sleep stages. He said that while the device most likely had a rough sense of when he was sleeping and awake, he didn’t know whether the information about sleep stages was accurate — let alone what to do with it.

“There’s no program — it’s just information,” Dr. Weiss said. “The question is can you do anything on your own to optimize it? Or is the information just worthless or is it making things worse? Sometimes being aware of it just makes you even more anxious.”

Dr. Vallat shared similar concerns. One big problem, he said, is that many of these tracking apps send daily notifications with users’ sleep statistics. He suggested that people experimenting with sleep trackers look at weekly trends, not daily summaries.

“It’s a vicious cycle, because if you immediately feel you didn’t sleep enough, it will impact your mood,” he said.

Dr. Grandner of the University of Arizona said that consumer-grade sleep tracking was in its early stages and that it was too soon to tell what people should do with the data.

“For a person to be worrying about their sleep stages is like being worried about the gas makeup of the air you’re breathing in,” he said.

How to Get a Better Night’s Sleep

How do you become a more successful sleeper? Grab a pillow, curl up and keep reading to find out.

Makers of sleep tech and scientists can agree on one thing: Sleep-tracking apps and devices can be useful for getting a broad look at your sleep, but people should resist drawing conclusions about their sleep health.

Mr. Walsh, the developer of AutoSleep, said people should use his app to look at trends, not to obsess over the daily data.


“I’ve had plenty of customers say this has changed their life, but I get other people saying they’re waking up in the middle of the night and checking their sleep,” he said. “I tell them to go back to sleep.”

Fitbit said in a statement that it took accuracy very seriously and that its team continuously studied and tested the accuracy of its products. Apple did not immediately have a comment.

Dr. Vallat told me that if I really wanted to get better sleep, I should simply try to sleep and wake up at the same time every day — that would help my brain learn how to build a structure for optimal sleep. He also advised making the bedroom a cool environment (about 68 degrees) and as dark as possible; avoiding alcohol in the evening; not checking email or social media right before bed; and asking myself each morning when I woke up, “Do I feel refreshed?”

That all sounded reasonable — and there’s no app needed for any of that.

Related Coverage
Tech Can Hurt Our Sleep. So I Tried Bose Sleepbuds for Help.

That Sleep Tracker Could Make Your Insomnia Worse

Maybe Your Sleep Problem Isn’t a Problem

Brian X. Chen is the lead consumer technology writer. He reviews products and writes Tech Fix, a column about solving tech-related problems. Before joining The Times in 2011 he reported on Apple and the wireless industry for Wired. @bxchen

A version of this article appears in print on , Section B, Page 6 of the New York edition with the headline: Data That May Keep You Up at Night. Order Reprints | Today’s Paper | Subscribe

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.