A good night’s sleep can help you feel rested and recharged, while poor or lack of sleep can affect your sense of well-being and cognitive functioning and even lead to long-term health problems. Yet for too long, people have ignored sleep problems, attributing them to stress or anxiety. However, tracking your sleep can be particularly important if you suffer from sleep disorders such as sleep apnea.
Sleep apnea is a condition in which breathing repeatedly stops and starts during sleep. The most common is obstructive sleep apnea, or OSA, in which breathing can stop for more than 10 seconds, in some cases up to 100-120 seconds, repeatedly. The death earlier this year of veteran music composer Bappi Lahiri focused attention on this disorder.
This is where fitness wearables can help. As someone who suffers from OSA, I’ve been using these (Fitbit Sense, for the time being) to track my sleep patterns. I can also monitor the improvement, if any, by changing a pillow or using a sleeping pill. Of course, you should consult a doctor if you think you have a problem; Fitness wearables are not a substitute.
While older fitness trackers used to monitor wrist movement to monitor sleep, the recent generation also monitors heart rate and factors like body temperature and snoring. The most advanced ones even include an SpO2 sensor to track blood oxygen levels. The trackers monitor the duration and quality of sleep, as well as the stages of sleep, reporting the phases in which you were awake, tossing and turning.
During a typical night, we go through several stages. Stage one is an extremely light sleep state. In stage two, our brain waves begin to slow down. In stages three and four, called deep sleep, our bodies grow and repair themselves. The final stage is called rapid eye movement (REM). During this, our brains become more active and dreams occur. The cycle repeats every 90-110 minutes. Missing any stage is a sign of lack of sleep.
Since looking at and dissecting all the data can be overwhelming, fitness wearables and their companion apps break it down into meaningful information and an easy-to-follow “sleep score.” Earlier this year, Fitbit went even further by introducing a sleep profile that offers a longitudinal analysis of sleep patterns, essentially, over a period of time. Since sleep can vary significantly from night to night, it’s a good idea to analyze sleep data over a longer period to find out, for example, the time spent in light, deep, and REM sleep, plus the time spent awake , as well as how sleep is related to activity, mood, and more.
A sleep profile or long period of evaluation through sleep trackers offers an advantage over a traditional sleep study in that it is difficult and costly to have sleep specialists in the home for too many days.
This is where fitness wearables can help. As someone who suffers from OSA, I’ve been using these (Fitbit Sense, for the time being) to track my sleep patterns.
(fitbit)
How accurate is it?
My ear, nose and throat doctor reckons that a reliable fitness tracker can accurately detect snoring and control restless sleep patterns. But, and that’s a but repeated by most experts, sleep trackers are not diagnostic. Lead neurologist and sleep specialist Manvir Bhatia, director of the Center for Sleep Neurology in Delhi, believes that people who snore and have excessive daytime sleepiness should be tested for OSA. An estimated 80% to 90% of adults with OSA remain undiagnosed, he adds.
Also, since they don’t measure sleep directly and rely primarily on movement and heart rate for assessment, fitness trackers are of limited use. They measure inactivity as a surrogate for estimating sleep and one can fool a tracker by going to bed quietly while awake. Therefore, these portable devices often underperform in people with insomnia.
Still, fitness trackers have their uses. Sleep tracking raises awareness and offers early warning signs of a disorder. My family doctor says that troublesome sleep patterns can also be indicative of larger health problems. How often has a doctor asked you, “Are you sleeping well?”
A recent study published in the US National Sleep Foundation journal Sleep Health, conducted to evaluate the performance of a wrist-based reflectance pulse oximeter, concluded that Samsung’s Galaxy Watch 4 could help measure the OSA. He found that wrist trackers integrated with reflectance PPG (photoplethysmography) sensors were accurate in continuously measuring oxygen levels, allowing researchers to detect OSA.
Fitbit sleep score in the iOS app.
(fitbit)
What are my options?
Before you indulge in sleep tracking on your fitness tracker, or buy a new one for it, keep in mind not to obsess over sleep data. A 2017 study published in the Journal of Clinical Sleep Medicine highlighted a downside of obsessive sleep tracking called “orthosomnia.” The condition where people obsessively seek optimal sleep based on insights derived from sleep tracking can cause stress and anxiety, which in turn can negatively affect sleep.
As a reviewer, I often compare data between different wearable devices, but I suggest other people not to worry about it. Just pick a credible one like the one from the options below, and don’t overthink it. Also, a sleep tracker, wearable or not, may often not be 100% accurate when compared to a professional sleep study (polysomnogram). However, these are really trends over time. Again, don’t worry about that.
To reiterate, if you have any concerns about the quality of your sleep, it’s a good idea to talk to a doctor. However, if you want insight into your sleep, wearable fitness devices are a great option. Instead of absolute numbers, keep an eye out for trends to improve your sleep routine and, in the event of an abnormality, see a sleep specialist. Sleep well!
Fitbit: When it comes to wearable fitness devices available in India, Fitbit arguably offers the best sleep tracking with the most comprehensive insights. And that’s across its entire portfolio: smartwatches including the Fitbit Sense and Fitbit Versa 3, as well as trackers like the Fitbit Charge 5 and Fitbit Luxe.
The heart rate sensor works in conjunction with the SpO2 sensor to unlock estimated oxygen variation while you sleep. Large swings in blood oxygen levels can be a sign of sleep disorders like OSA. Plus, Fitbit Sense can even track when you store. This and other insights like duration breakdown, sleep stages, etc., with detailed graphs, though require a Fitbit Premium.
The Fitbit Versa series health and fitness watch also has sleep tracking features.
(fitbit)
xiaomi: Xiaomi’s Mi Band has been one of the best-selling affordable fitness trackers for a while now. The Mi Band 6, as well as the Redmi Watch 2 Lite and Redmi Smart Band Pro, is a solid sleep tracking option if you’re on a budget.
Sleep tracking is sometimes a bit inconsistent for REM sleep versus a Fitbit Sense, but that’s not a hit. The app offers a comprehensive sleep summary that helps you better understand your sleep. Considering its price, it’s a pretty rewarding proposition.
In the affordable segment, there is also the Amazfit portfolio with some attractive smartwatches. It offers sleep analysis similar to Xiaomi devices, but often tends to overestimate sleep time; however, one should focus on trends rather than absolute accuracy.
apple watch: The Apple Watch, otherwise the most popular smartwatch globally, only got the ability to track sleep natively in 2021, and the company’s view on sleep monitoring is pretty limited.
There is no sleep stage tracking for REM, deep, and light cycles, nor is there any in-depth analysis of your sleep. There’s also no Fitbit-style “sleep score.” Apple Watch offers details about the duration of your sleep along with the dark and light periods of your sleep. It is a basic breakdown, but also quite reliable. That said, Apple Watch users can try third-party apps for more detailed information.
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