--- title: Apple Watch: The Most Accurate Wearable for Heart Rate description: In a new study, the Apple Watch fitness tracker was about 90% accurate at measuring heart rate canonical: https://time.com/4527843/accurate-wearable-apple-watch-fitness-tracker/ author: Mandy Oaklander article:opinion: false article:content_tier: free article:published_time: 2016-10-12T15:00:08.000Z article:modified_time: 2023-12-13T17:52:44.000Z article:section: Health og:title: This Is The Most Accurate Wearable og:description: In a new study, the Apple Watch fitness tracker was about 90% accurate at measuring heart rate og:url: https://time.com/4527843/accurate-wearable-apple-watch-fitness-tracker/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltb1a7022a28215504/6988a9a20a4a2259519cb9bd/apple-watch.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: apple watch og:type: article twitter:card: summary_large_image twitter:title: This Is The Most Accurate Wearable twitter:description: In a new study, the Apple Watch fitness tracker was about 90% accurate at measuring heart rate twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltb1a7022a28215504/6988a9a20a4a2259519cb9bd/apple-watch.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # The Apple Watch Is the Most Accurate Wrist Wearable  by [Mandy Oaklander](https://time.com/author/mandy-oaklander/)  ## Mandy Oaklander Oaklander is a senior editor at TIME. Updated: Dec 13, 2023 5:52 PM UTCPublished: Oct 12, 2016 3:00 PM UTC  A customer views an Apple Watch Series 2 displayed at an Apple Inc. in New York, U.S., on Friday, Sept. 16, 2016\. Shoppers looking to buy Apple Inc.'s new iPhone 7 smartphones on Friday better have ordered ahead. Brisk demand left some stores sold out, leaving those who purchased online with the best chance to get their hands on the latest models -- and some resorting to extreme measures. Photographer: John Taggart/Bloomberg via Getty Images A customer views an Apple Watch Series 2 displayed at an Apple Inc. in New York, U.S., on Friday, Sept. 16, 2016\. Shoppers looking to buy Apple Inc.'s new iPhone 7 smartphones on Friday better have ordered ahead. Brisk demand left some stores sold out, leaving those who purchased online with the best chance to get their hands on the latest models -- and some resorting to extreme measures. Photographer: John Taggart/Bloomberg via Getty ImagesGetty Images  by [Mandy Oaklander](https://time.com/author/mandy-oaklander/)  ## Mandy Oaklander Oaklander is a senior editor at TIME. Updated: Dec 13, 2023 5:52 PM UTCPublished: Oct 12, 2016 3:00 PM UTC **Updated** Some fitness trackers are a [lot more accurate than others](http://time.com/4344675/fitbit-lawsuit-heart-rate-accuracy/?iid=sr-link1), finds a new study published in _JAMA Cardiology._ Researchers at Cleveland Clinic wanted to test how well four popular [wearable devices](http://time.com/4517033/fitness-tracker-fitbit-zip-exercise/?iid=sr-link3) measured heart rate, which is involved in a formula that calculate how many calories a person is burning while they exercise. They hooked 50 healthy adults up to an electrocardiogram (EKG), the gold-standard test for measuring heart activity, and compared the results to heart rates obtained by [Fitbit Charge HR](https://www.amazon.com/gp/product/B00N2BW2PK/ref=as%5Fli%5Ftl?ie=UTF8&tag=timetechgadgets-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00N2BW2PK&linkId=673d51b4b1c9aaaee1a2656d496a2a4a), Apple Watch, [Mio Alpha](https://www.amazon.com/gp/product/B00N3NH1A8/ref=as%5Fli%5Ftl?ie=UTF8&tag=timetechgadgets-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00N3NH1A8&linkId=eae85d575b813d4d5ba3f8f16a298baa) and Basis Peak. They also assessed a chest strap. The researchers measured everyone at rest, then walking and jogging on a treadmill. The chest strap monitor was the most accurate, nearly matching the EKG with 99% accuracy—both technologies capture electrical activity coming from the heart. Of the wrist wearables, Apple Watch was about 90% accurate, but “the other ones dropped off into the low 80s for their accuracy,” says Dr. Gordon Blackburn, one of the study’s authors and director of cardiac rehabilitation at Cleveland Clinic. Accuracy also went down as intensity increased. “What we really noticed was all of the devices did not do a bad job at rest for being accurate for their heart rate, but as the activity intensity went up, we saw more and more variability,” Blackburn says. “At the higher levels of activity, some of the wrist technology was not accurate at all.” Measuring heart rate from the wrist is convenient, but it comes with some disadvantages. “All of the wrist technologies are looking at blood flow,” Blackburn says. “You need to have good contact between the photosensing cells; as a person is exercising more vigorously, there’s more bounce, so you may lose some of that contact.” For a person without health problems using a wrist-worn device to track heart rate, “it probably isn’t putting them at any risk,” Blackburn says. “Our concern is for patient populations that have health problems that can be aggravated by getting to too high of an intensity.” “Fitbit trackers are not intended to be medical devices. Unlike chest straps, wrist-based trackers fit comfortably into everyday life, providing continuous heart rate for up to several days without recharging (vs. a couple hours at a time) to give a much more informative picture of overall health and fitness trends,” Fitbit representatives said in a statement, adding that their internal tests showed an accuracy rate of 94% \[or a margin of error that was about 6%.\] ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4527843/accurate-wearable-apple-watch-fitness-tracker/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4527843/accurate-wearable-apple-watch-fitness-tracker/"},"headline":"The Apple Watch Is the Most Accurate Wrist Wearable","datePublished":"2016-10-12T15:00:08.000Z","dateModified":"2023-12-13T17:52:44.000Z","description":"In a new study, this fitness tracker was about 90% accurate at measuring heart rate","url":"https://time.com/4527843/accurate-wearable-apple-watch-fitness-tracker/","keywords":["Exercise & Fitness","Fitbit","Wearables","Apple watch"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/bltb1a7022a28215504/6988a9a20a4a2259519cb9bd/apple-watch.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Mandy Oaklander","jobTitle":"Oaklander is a senior editor at TIME.","url":"https://time.com/author/mandy-oaklander/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/bltb1a7022a28215504/6988a9a20a4a2259519cb9bd/apple-watch.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"apple watch","caption":"apple watch","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/exercisefitness/","name":"Exercise & Fitness"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4527843/accurate-wearable-apple-watch-fitness-tracker/","name":"The Apple Watch Is the Most Accurate Wrist Wearable"}}]}] ```