Smartwatches can do lots of cool things, but how well do they track sleep? What technology do they use? How accurate are they? We’ll take a look.
Smartwatches can now measure sleep. This is a feature that was previously only available on fitness trackers, but smartwatch manufacturers have adopted the technology to create even fancier-looking devices – and at a lesser price.
Sleep is an important part of living a healthy life, but how do smartwatches measure sleep? That’s exactly what we’ll be looking into in this article. Let’s see what’s sleep tracking is all about, its importance and its use cases.
What is Sleep Tracking?
Sleep tracking is a feature of some fitness trackers, smartwatches and other wearables that allows users to see how well they’re sleeping.
The devices typically monitor sleep patterns by tracking your movements during the night. Some trackers will also analyze your sleep quality based on heart rate and noises you make while you’re asleep.
Devices that do this are able to monitor how many hours you sleep, how long it takes you to fall asleep, how many times you wake up and what time you were in deep sleep.
The goal of sleep tracking is for users to be able to use the information to improve their overall health and get more rest each night. We will see shortly how does a smartwatch measure your sleep so easily.
Is Sleep Even Important?
Sleep is important. It is a time to rest, recharge, and gain energy to be more productive when you are awake. The effects of sleep on your body are immediate and well-known.
Your heart rate slows, your blood pressure decreases, your lungs expand, and your muscles relax. We all know that when we are tired and have had a lack of sleep our body reacts by slowing down.
Similarly, if you have had a good night’s sleep then your body feels refreshed and energized the next day. Your brain also undergoes some amazing changes during the night.
When you sleep you experience a burst in growth hormones that aid in cellular repair, maintain healthy tissue function, and promote growth.
You also experience an increase or release of neurotransmitters like norepinephrine, serotonin, and others that can help produce a good mood the next day.
Sleep helps to build memories as well so if you are chronically sleep-deprived over time it will affect your ability to learn new things as well as retain what you have already learned.
Sleep is also important for reducing stress levels because as you sleep your body releases Human Growth Hormone (HGH) which helps to reduce cortisol levels in the body associated with stress.
A study at the University of Pennsylvania in 2005 showed that students who slept for eight hours a night received A’s and B’s, while those who got less than six hours generally received C’s or lower. A study from the University of California-Berkeley found similar results, with GPA’s declining as sleep decreased. The National Sleep Foundation claims that sleep deprivation is linked to memory loss, depression and other problems.
How Do Smartwatches Measure Sleep?
If you have a smartwatch, it’s likely that you have access to your sleep data. Many apps on smartwatches and fitness bands have the ability to not only track your sleep but also give you feedback on how to improve your quality of sleep.
When it comes to tracking your sleep, wearables use different methods than traditional methods of measuring such as using a sleep study or actigraphy watch, which measures movement.
Wearables use heart rate variability (HRV) and movement, meaning there is no need for electrodes. Instead, devices can detect all the movements in your night’s rest, including the number of times you wake up during the night and how long it takes you to fall back asleep.
Smartwatches can measure sleep by tracking movement in three dimensions – up-and-down, left-to-right and backwards-and-forward – over a period of time.
For example, if you were sleeping on your side with your arm bent at the elbow and your hand tucked under your pillow, smartwatch sensors could sense that position and record it as sleeping on your side.
By doing this thousand or millions of times, smartwatches can monitor when you are lying still or asleep and when you are restless or awake. In general, smartwatches use two methods to measure your sleep effectively.
Smartwatches Measure Sleep by Two Methods
There are currently a couple of different methods that smartwatches use to track sleep. Most devices measure motion using an accelerometer.
As you move throughout the night, the device can determine when you’re asleep and when you’re awake. Key advantages of this method are that it is easy to implement and it can be used to track sleep on its own without any other supporting hardware.
The major disadvantage of this method is that it measures movement rather than sleep stages. In order to get a more detailed analysis, you need additional sensors like heart rate monitors and respiration sensors which add cost and complexity to the watch.
A variation on this approach is to use a combination of an accelerometer with heart rate and gyroscope data.
A second method for measuring sleep uses heart rate data from an optical sensor on the back of the watch or wristband to determine your pulse during the night.
By measuring changes in your heart rate at regular intervals during sleep, smartwatches can detect different stages of sleep (light, deep etc.). A watch that monitors your heart rate can give you an idea of how well you are sleeping.
The smartwatch measures your heart rate while you sleep, so it can tell if you wake up frequently at night. If your resting heart rate increases significantly over the course of the night, it could be a sign of sleep apnea.
How Valuable is Sleep Tracking Info?
Why is sleep so important? Sleep is the time when your body restores, recharges and heals itself. If you are getting enough good quality sleep, you are more likely to feel refreshed and energized.
You may also be healthier. Research shows that people who don’t get enough sleep have a higher risk of chronic health conditions such as diabetes, heart disease, stroke, high blood pressure and obesity.
In fact, The Centers for Disease Control and Prevention (CDC) reports that more than 70 million U.S. adults report they are not getting enough sleep on an ongoing basis.
Sleep helps the brain to flush away toxic proteins that build up during waking hours. The findings, published in the journal Science, show that specific compounds are removed from the brain during sleep.
“We think this clean-up process is important. It’s like a dishwasher for the brain,” lead author Dr Sigrid Veasey, from Brigham and Women’s Hospital in Boston, US, said.
The study found that sleep plays an important role in regulating the body’s response to injury and disease. Overall, smartwatches are extremely popular in India because they provide multiple health-related measurements.
Look at your sleep patterns over a couple of weeks
On average, you need between seven and nine hours of sleep each night to function at your best. If you’re consistently waking up feeling fatigued in the morning or if you’re consistently falling asleep at inappropriate times during the day, your body may be telling you that it needs more sleep.
Smartwatches’ user-friendly dashboard displays detailed sleep data. You can self-analyse it or see your doctor for analysis.
Trying to catch up on lost sleep by extending your sleeping hours into a second or even third shift can actually make matters worse. Your body will adjust to the new schedule and continue to feel tired during the day.
So when should you seek help? If sleeping longer than usual isn’t helping, consider talking to your doctor about other options.
Try keeping a log of your sleeping habits for a couple of weeks to see whether there are any patterns that might be contributing to your fatigue.
For example, if you’re frequently waking up at 3 a.m., it’s reasonable to assume that something is waking you from sleep during that time period – whether it’s work stress, noise from neighbours or just bad dreams.
Conclusion | How Does Smartwatch Track Sleep?
The article explains how smartwatches help to improve the sleep of people. They do this by analyzing different aspects of sleep and using this analysis to alert the person when they are entering deep sleep, light sleep, or being woken up too much during sleep.
While none of these smartwatches are perfect, they are a step in the right direction and a sign of the level of innovation taking place in the wearable market. Overall, apps for smartwatches can be better at monitoring sleep than dedicated fitness watches.