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Newest Smartwatches Move From Tracking Fitness to Monitoring Health

Added features can keep you heart-healthy — and may detect signs of COVID-19

spinner image Apple Watch Series 6 - Displaying blood oxygen measurements
Apple Watch Series 6 displaying a blood oxygen reading.
Apple, Inc.

The pandemic may have kept you a bit more stationary than you would have preferred these past couple of years. But because of COVID-19 and its variants, you may be more eager than ever to track your fitness activity and get a better handle on what’s happening inside your body.

Insights into your health may come straight from your wrist. Apple’s latest Series 7 smartwatch, which starts at $399, coupled with the watch OS 8 software upgrade that some older models can take advantage of, can help you measure your cardio fitness and blood oxygen consumption while also detecting irregular heartbeats, excessive exposure to loud noises and how much sleep you’re getting.

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The watches can even remind you to wash your hands periodically, with a 20-second countdown timer that may automatically kick in to ensure you’re washing long enough. And recent Apple Watches can summon emergency medical assistance should you fall and become immobilized.

Rival wearables from Fitbit (now owned by Google), Samsung and other companies also are providing digital biomarkers that provide visibility into your health — well beyond the steps counted and calories burned that have long defined such devices.

As for Google, it hasn’t revealed much publicly yet about its Pixel Watch, scheduled for a fall 2022 release. But this new watch will bake in some Fitbit features and run off the latest version of Google’s Wear OS software platform, the flavor of Android designed for wearables.

spinner image Sleep tracking functions on Fitbit Sense health tracking smart watch wearable device, San Ramon, California, September 22, 2020. (Photo by Smith Collection/Gado/Getty Images)
Sleep tracking functions on a Fitbit Sense smartwatch device
Smith Collection/Gado/Getty Images

“This is a new era where we have an opportunity to reach the patients outside the walls of the hospital,” says Nino Isakadze, M.D., a cardiologist at Johns Hopkins Hospital in Baltimore who studied atrial fibrillation (A-fib) and wristband technology during her residency. “Patients can be empowered by having this type of data, and be able to track their progress and be more aware of their health overall.”

Smartwatches share data with companion health apps on your iPhone or Android devices. For those enrolled in Medicare Advantage or other insurance plans, it’s worth noting that some smartwatches are available at a discount as a member benefit.

4 features on some smartwatches

1. Electrocardiogram. In 2018, Apple took a major step in putting power in the hands of consumers when it added an electrocardiogram app to its Series 4 Apple Watch models, which has carried over to the Series 5, Series 6 and Series 7. The app, which is called ECG rather than the more commonly known EKG abbreviation, can detect A-fib, an irregular heartbeat that is a major risk factor for blood clots and stroke, and has clearance from the Food and Drug Administration (FDA).

Google’s Fitbit also received regulatory clearance from the FDA for its own EKG app, now on the Fitbit Sense health-oriented watch and Charge 5 devices. And Samsung has added its own FDA-cleared heart-monitoring ECG app to the Galaxy Watch4, which starts at $300. Older models, such as the Galaxy Watch3 and Galaxy Watch Active2, which you might still find at reduced prices, also have the feature.

Electrocardiograms measure the timing and strength of the electrical pulses that keep your heart pumping. On the Apple Watch, the ECG kicks into action when you launch the app and hold your finger against the digital crown, the home button on the upper right side of the watch, for 30 seconds. Electrodes are built into the back crystal and digital crown of the watch.

If you receive a “sinus rhythm” result, it means the watch has detected a normal heartbeat, not A-fib. Regardless of the result, you’re urged to seek medical attention if you experience any symptoms. Apple makes it clear that its watch does not check for signs of a heart attack.

Fitbit announced that more than 2 million users have officially enrolled to receive irregular heart rhythm notifications about possible A-fib since the feature, which works across several models, received FDA clearance in April. It is powered by Fitbit’s photoplethysmography (PPG) algorithm, which passively assesses your heart rhythm in the background while you’re still or sleeping.

2. Measuring the skin. Fitbit has added an electrodermal (EDA) sensor to its Fitbit Sense watch ($240). When you place your palm over the face of the device, sensors can detect subtle electrical changes in the sweat level of your skin. Factored with your heart rate, sleep and activity data, Fitbit calculates a stress management score between 1 and 100, with a higher number translating to fewer physical signs of stress and a lower number meaning more signs.

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Fitbit may recommend breathing exercises and other mindfulness tools to help you manage the stress. But after a free trial period, you’ll have to sign up for a premium subscription service for a deeper dive into the metrics. The subscription costs $10 monthly or $80 annually.

Another dedicated sensor on the Fitbit Sense can detect variations in skin temperature. This feature is not yet available on Apple or Samsung smartwatches.

3. Sleep tracking. Some devices, including high-end Fitbits and Galaxy smartwatches, track the quality of your slumber time right down to various sleep stages and the number of times you wake up in the middle of the night. Apple’s watch is more about setting up the conditions so you get a good night’s sleep, starting with a wind-down routine before bedtime. But it, too, will be adding the ability to detect sleep stages via the watch OS 9 software update coming in the fall.

Of course, if you’re planning to sleep with any of the smartwatches, make sure they are charged before you go to bed, and if needed, give them some extra juice when you wake up. Only the Fitbit Sense had longer than a 24-hour day’s battery life in what PC Magazine considered normal use.

4. Blood oxygen. Fitbit, Garmin, Mobvoi and Samsung all have certain models that can measure blood oxygen levels. The Apple Series 6 and Series 7 obtain a measurement from a quartet of clusters of green, red and infrared LEDs on its rear and four photodiodes spaced and isolated between them to determine the color of your blood.

Measurements are automatically collected throughout the day or when you’re asleep. You also can launch an app to take a manual reading by steadying your wrist on a table, with the watch display facing upward, tapping Start, and then waiting patiently while a timer counts down for 15 seconds.

While most healthy adults report blood oxygen levels between 95 and 100 percent, what does a lower reading signify? Blood oxygen is an indicator of early signs of circulatory, heart or lung function issues, such as anemia, neurological problems or sleep disorders, says Leslie Saxon, M.D., a professor of medicine and executive director at the Center for Body Computing at the University of Southern California.

Are Smartwatches Worth It?

Keep results in perspective

Don’t freak out if any result is out of kilter, but see how it compares with your baseline. Yet don’t ignore warning signs either.

“The most important thing is how one is feeling and the symptoms,” Isakadze says. “If someone is not feeling well, I would say no matter what the numbers show on the oxygen levels or the ECG, it would still be very important to seek care.”

These are still early days for what smartwatches can track. Neither the Apple Watch nor the Fitbit can monitor blood glucose levels or high blood pressure without the use of other devices right now, which would provide a huge benefit to patients with diabetes or hypertension.

But specialized wearables are in the works.

A startup called Movano completed a second pilot study in February that tested a noninvasive, needle-free wrist-worn prototype that captured glucose, blood pressure and other health data estimates. 

Swiss startup firm Aktiia announced plans to bring its automated, wrist-worn 24/7 blood pressure device to the United States, but it must gain FDA approval first.

Omron Healthcare, a global electronics firm based in Japan, already sells an FDA-approved HeartGuide wristwatch for $499 that can monitor blood pressure. Patients must initiate readings manually.

If you don’t want to carry your smartphone with you when you’re out for a run or doing other exercise, get a smartwatch that has a cellular connection. This will give you much of a phone’s functionality on your wrist. Smartwatches without cellular connectivity are more like an extension of your phone and will work well only when near that device.

Meanwhile, data culled from the wrist is becoming fertile ground for researchers.

In 2020, Apple announced a study with Anthem and the University of California, Irvine, to examine how its watch might help individuals manage asthma. Another ongoing Apple study, with the Ted Rogers Centre for Heart Research at the Peter Munk Cardiac Centre in Toronto, is investigating how its watch might lead to better outcomes for patients with heart failure.

“Looking at data from wearables such as Apple Watch and partnering to understand the patient experience, coupled with the information from sensor technology, is a way for us to develop the knowledge that will allow us to take better care of patients. This is the future,” says Heather Ross, M.D., at the University of Toronto.

Behavioral health experts at UCLA are collaborating with Apple on a digital health study to measure how factors like sleep, physical activity, heart rate and daily routines relate to symptoms of depression and anxiety. Data comes from the Apple Watch and iPhone.

While the results of such studies will take time, you can learn a lot by looking at your wrist right now.

This story, originally published Sept. 28, 2020, was updated to reflect newer models and industry developments.

Edward C. Baig is a contributing writer who covers technology and other consumer topics. He previously worked for USA TodayBusinessWeekU.S. News & World Report and Fortune and is the author of Macs for Dummies and coauthor of iPhone for Dummies and iPad for Dummies.

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