Skip to main content

Just how accurate is your wearable? Not very, new study finds

Stop glancing at your wrist in the middle of your circuit — your fitness tracker probably isn’t telling you what you need to know. At least, that’s what a new study from Cleveland Clinic’s Heart and Vascular Institute suggests. As per the latest findings published in a “research letter” by JAMA Cardiology, wrist wearables like the Fitbit and Apple Watch just aren’t that great at keeping tabs on your heart rate, often cited as a key metric to watch during your workout. Apparently, you can’t really rely on your wearable to tell you what’s going on.

In conducting the tests, the Cleveland team examined the Apple Watch, Mio Fuse, Fitbit Charge HR, and Basis Peak. Study participants were connected to an electrocardiogram (EKG), the most accurate measure of heart rate currently available, and were also asked to wear the trackers while running on a treadmill at speeds of 2, 3, 4, 5, and 6 miles per hour.

Recommended Videos

“All worked pretty well at rest,” said Dr. Marc Gillinov, the Cleveland Clinic cardiac surgeon who led the experiment. “But as people exercised, the accuracy diminished.”

Ultimately, Gillinov found that none of the fitness wearables were as accurate as a chest strap monitor, though the Apple Watch and Mio Fuse came closest. The now-defunct Basis Peak, however, overestimated heart rate, while the Fitbit Charge HR underestimated heart rate during vigorous exercise.

But Fitbit remained adamant that its devices are trustworthy, noting, “Fitbit devices were tested against properly calibrated industry devices like an EKG chest strap across the most popular activities performed worldwide, including walking, running, biking, elliptical and more.” This isn’t the first time Fitbit has faced criticism over inaccuracies in their measurements (and the company itself admits that its wearables are not meant to be medical devices).

Study co-author Gordon Blackburn, a cardiac researcher at the Heart and Vascular Institute at Cleveland Clinic, told the Verge that accuracy became particularly contentious when heart rates reached 100 beats per minute, and became “very inconsistent above 130 and 140 beats per minute.” This is problematic as these ranges are quite common for healthy individuals to aim for while exercising. “Patients come in with data and they say, ‘I’m exercising and my heart rate is going sky high,’ or ‘I can’t get into the zone’ and they’re getting frustrated,” he said. “The people developing these trackers say it’s not a medical technology, but that message isn’t being absorbed by users. And we’re caught in the middle when they come into the office presenting data and we have to convince them there is significant error.”

Of course, this doesn’t mean that you should just be chucking your wearables out the window.

Dr. Mitesh Patel, an assistant professor of medicine at the University of Pennsylvania’s Perelman School of Medicine in Philadelphia, was not involved in the new study, but specializes in the impact of technology-based interventions on behavior. “For the general consumer, wearable devices may still be able to give them a general sense of their heart rate trends,” Patel told CBS News. “However, further study is needed to determine which devices are more reliable for use in clinical care.”

Lulu Chang
Fascinated by the effects of technology on human interaction, Lulu believes that if her parents can use your new app…
Digital Trends’ Top Tech of CES 2023 Awards
Best of CES 2023 Awards Our Top Tech from the Show Feature

Let there be no doubt: CES isn’t just alive in 2023; it’s thriving. Take one glance at the taxi gridlock outside the Las Vegas Convention Center and it’s evident that two quiet COVID years didn’t kill the world’s desire for an overcrowded in-person tech extravaganza -- they just built up a ravenous demand.

From VR to AI, eVTOLs and QD-OLED, the acronyms were flying and fresh technologies populated every corner of the show floor, and even the parking lot. So naturally, we poked, prodded, and tried on everything we could. They weren’t all revolutionary. But they didn’t have to be. We’ve watched enough waves of “game-changing” technologies that never quite arrive to know that sometimes it’s the little tweaks that really count.

Read more
Digital Trends’ Tech For Change CES 2023 Awards
Digital Trends CES 2023 Tech For Change Award Winners Feature

CES is more than just a neon-drenched show-and-tell session for the world’s biggest tech manufacturers. More and more, it’s also a place where companies showcase innovations that could truly make the world a better place — and at CES 2023, this type of tech was on full display. We saw everything from accessibility-minded PS5 controllers to pedal-powered smart desks. But of all the amazing innovations on display this year, these three impressed us the most:

Samsung's Relumino Mode
Across the globe, roughly 300 million people suffer from moderate to severe vision loss, and generally speaking, most TVs don’t take that into account. So in an effort to make television more accessible and enjoyable for those millions of people suffering from impaired vision, Samsung is adding a new picture mode to many of its new TVs.
[CES 2023] Relumino Mode: Innovation for every need | Samsung
Relumino Mode, as it’s called, works by adding a bunch of different visual filters to the picture simultaneously. Outlines of people and objects on screen are highlighted, the contrast and brightness of the overall picture are cranked up, and extra sharpness is applied to everything. The resulting video would likely look strange to people with normal vision, but for folks with low vision, it should look clearer and closer to "normal" than it otherwise would.
Excitingly, since Relumino Mode is ultimately just a clever software trick, this technology could theoretically be pushed out via a software update and installed on millions of existing Samsung TVs -- not just new and recently purchased ones.

Read more
How does Garmin measure stress, and is it really accurate?
Garmin Vivomove Sport dial close up. Credits: Garmin official.

Garmin watches are known for their robust activity tracking, but that's not all these fitness watches can do. Over the years, the company has been adding wellness features to its lineup of watches. These new health-focused metrics allow people to analyze their fitness and identify outside factors affecting their performance. One such factor is stress, which is something Garmin watches actively measures.
But you may be wondering—exactly how does Garmin measure stress? In this article, we break down how Garmin measures stress and delve into the accuracy of this metric. Should you trust your stress score? Read on to find out.

Is Garmin's stress score accurate?

Read more