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Apple Watch Proves Most Accurate at Measuring Heart Rate in New Fitness Tracker Study

In a new study comparing the accuracy of seven different fitness trackers, the Apple Watch was found to have the lowest margin of error when measuring heart rate, beating the Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, PulseOn, and Samsung Gear S2.

Researchers set out to determine the accuracy of wrist-worn devices at measuring both heart rate and energy expenditure, aka calories burned via physical activity. 60 volunteers participated, including 29 males and 31 females, each of whom wore several fitness trackers and completed activities like cycling, running, and walking.


Data gathered by the fitness devices was compared against a "gold standard" tracking method, which included an electrocardiograph (ECG) for measuring heart rate and clinical grade indirect calorimetry (measuring oxygen and carbon dioxide expelled when breathing) for measuring calories burned. An error rate of 5 percent was determined to be within acceptable limits.

Across all of the modes of activity, the Apple Watch had the lowest median heart rate error at 2 percent (1.2% to 2.8%), while the Samsung Gear S2 had the highest error rate at 6.8 percent (4.6% to 9%). The Apple Watch was also notably more accurate at measuring heart rate during the walking test than competing products.
For the walking task, three of the devices achieved a median error rate below 5%: the Apple Watch, 2.5% (1.1%-3.9%); the PulseOn, 4.9% (1.4%-8.6%); and the Microsoft Band, 5.6% (4.9%-6.3%). The remaining four devices had median error between 6.5% and 8.8%.
When it came to measuring calories, no device, Apple Watch included, managed to accurately determine how many calories were burned through activity. Median error rates across all devices and tasks ranged from 27.4 percent (Fitbit Surge) to 92.6 (PulseOn). Though no device was accurate, the Apple Watch did the best at estimating energy expenditure.


Overall, researchers found that most of the fitness trackers tested were able to measure heart rate with an acceptable error level in a laboratory setting, but calorie estimates are largely inaccurate.
There are three principal findings from the current study. In a diverse group of individuals: (1) most wrist-worn monitoring devices report HR with acceptable error under controlled laboratory conditions of walking, running and cycling; (2) no wrist-worn monitoring devices report EE within an acceptable error range under these conditions; (3) of the devices tested, the Apple Watch had the most favorable error profile while the Samsung Gear S2 had the least favorable error profile.
The full study, conducted by Stanford University and the Swedish School of Sport and Health Services, is available in the Journal of Personalized Medicine.

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Top Rated Comments

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20 months ago
Apple puts a lot into R&D and calibration. They know they're the biggest target when it comes to accuracy. Most wouldn't care if FitBit or Samsung aren't overly accurate but you'd see headlines everywhere if Apple were off.

Here's an interesting read on the level technicality they went through to make it incredibly accurate at telling time. It's 4x more accurate than the iPhone actually.

http://mashable.com/2015/12/30/apple-watch-synchronized/#EIku7j18gGq3
Rating: 21 Votes
20 months ago
So I read the article. Apple does something better than the competition. Then, just for laughs, I come here to the forum to read the howling and gnashing of teeth from the haters who want to tear them down.
I'm never disappointed, you guys are so entertaining! (& so full of it.) :)
Rating: 20 Votes
20 months ago
Why don't these studies ever compare the Apple Watch with more hardcore fitness watches like those from Garmin or Sunto?
Rating: 17 Votes
20 months ago

Why don't these studies ever compare the Apple Watch with more hardcore fitness watches like those from Garmin or Sunto?


Exactly. Garmin is such a giant in the fitness field, that to leave them out seems suspicious.
Rating: 13 Votes
20 months ago

Why don't these studies ever compare the Apple Watch with more hardcore fitness watches like those from Garmin or Sunto?


I'm not sure why the study didn't include a Garmin product. This was how the trackers were selected:

"Following a comprehensive literature and online search, 45 manufacturers of wrist-worn devices were identified. Criteria for inclusion included: wrist-worn watch or band; continuous measurement of HR; stated battery life >24 h; commercially available direct to consumer at the time of the study; one device per manufacturer. Eight devices met the criteria; Apple Watch; Basis Peak; ePulse2; Fitbit Surge; Microsoft Band; MIO Alpha 2; PulseOn; and Samsung Gear S2."
Rating: 11 Votes
20 months ago

Why don't these studies ever compare the Apple Watch with more hardcore fitness watches like those from Garmin or Sunto?

Especially galling since they bothered to include the discontinued Microsoft Band.
Rating: 9 Votes
20 months ago

Apple also put a lot of money into Stanford's pocket.

APPLE CHARITABLE MATCHING PROGRAM: Cook decided to put philanthropy on his agenda. Within weeks of taking the CEO position, Cook introduced Apple's charitable matching program, which matches employee contributions up to $10,000. Since the program's inception, it has donated more than $150 million to organizations such as Charity: Water, (Product RED), and Stanford University Hospitals, with Cook himself having donated $50 million a piece to each of the latter two.


That's great! And kudos to Apple and Mr. Cook for their philanthropy! The Stanford Medical Center is a worthy cause. Thanks for the heads-up on that.
Rating: 9 Votes
20 months ago

Apple puts a lot into R&D and calibration.


Apple also put a lot of money into Stanford's pocket.

APPLE CHARITABLE MATCHING PROGRAM: Cook decided to put philanthropy on his agenda. Within weeks of taking the CEO position, Cook introduced Apple's charitable matching program, which matches employee contributions up to $10,000. Since the program's inception, it has donated more than $150 million to organizations such as Charity: Water, (Product RED), and Stanford University Hospitals, with Cook himself having donated $50 million a piece to each of the latter two.
Rating: 6 Votes
20 months ago
Using the Apple Watch, I’ve progressed from running 8-10 kilometres per day to running 18-20. I still don’t care what my heart rate is though really most of the time. I assume it’s enough to keep me alive, which is really all I care about in the end.
Rating: 6 Votes
20 months ago
Tested mine last year vs. a Polar chest band at the gym and readings were very close.

the Samsung Gear S2 had the least favorable error profile.


Samsung being Samsung.
Rating: 6 Votes

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