{"id":591531,"date":"2026-09-06T02:32:17","date_gmt":"2026-09-06T02:32:17","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/591531\/"},"modified":"2026-09-06T02:32:17","modified_gmt":"2026-09-06T02:32:17","slug":"your-smartwatch-may-not-be-telling-you-the-whole-truth-about-calories-burned-researchers-say","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/591531\/","title":{"rendered":"Your smartwatch may not be telling you the whole truth about calories burned, researchers say"},"content":{"rendered":"<p><img decoding=\"async\" loading=\"eager\" fetchpriority=\"high\" src=\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/09\/Low-Res_Smartwatch-Testing.jpeg\"  alt=\"Your smartwatch may not be telling you the whole truth about calories burned, researchers say\"\/>  <\/p>\n<p>Your <a rel=\"nofollow noopener\" target=\"_blank\" href=\"https:\/\/www.independent.co.uk\/extras\/indybest\/kids\/best-kids-smartwatch-b1800994.html\">smartwatch<\/a> may not be telling you the truth about the <a rel=\"nofollow noopener\" target=\"_blank\" href=\"https:\/\/www.independent.co.uk\/life-style\/health-and-families\/track-calories-weight-loss-b3012133.html\">calories<\/a> you burn in a <a target=\"_blank\" rel=\"nofollow noopener\" href=\"https:\/\/www.independent.co.uk\/health-and-fitness\/dumbbell-workout-muscle-growth-fitness-b3039626.html\">workout<\/a> &#8211; with possible consequences for your <a rel=\"nofollow noopener\" target=\"_blank\" href=\"https:\/\/www.independent.co.uk\/news\/health\/glp1-obesity-us-children-weight-loss-drugs-b3043773.html\">weight loss<\/a>, a new<a rel=\"nofollow noopener\" target=\"_blank\" href=\"http:\/\/doi.org\/10.1371\/journal.pone.0353261\"> study<\/a> says.<\/p>\n<p>A test of four fitness trackers against clinical lab equipment showed that the devices overcount how many calories people burned, Florida International University said Monday.<\/p>\n<p>Unfortunately, the errors were the greatest for people with the highest body fat &#8211; who may be more likely to track calories, the researchers said.<\/p>\n<p>&#8220;You can&#8217;t treat the calories burned number it gives you as an accurate number, because it&#8217;s not,&#8221; lead author Jason Kostrna, an associate professor of kinesiology and exercise science, explained in a<a rel=\"nofollow noopener\" target=\"_blank\" href=\"https:\/\/news.fiu.edu\/2026\/your-smartwatch-is-lying-to-you-about-how-many-calories-you-burned-in-your-last-workout\"> statement<\/a>.<\/p>\n<p>&#8220;You could be off hundreds of calories each week and easily end up in a calorie surplus when you think you&#8217;re in a calorie deficit.&#8221;<\/p>\n<p>The researchers tested the watches on the wrists of 58 Hispanic adults who rode stationary bikes in 10-minute workouts that fluctuated between moderate and vigorous intensity.<\/p>\n<p>The watches included the Apple Watch Series 8, Fitbit Sense 2, Samsung Galaxy Watch 5 and Garmin Forerunner 955. They were all worn at the same time by a participant during each workout.<\/p>\n<p>Participants also wore a COSMED K5 metabolic analyzer: a device strapped to their back with an attached face mask that measures their breath, oxygen consumption and how much energy they were expending.<\/p>\n<p>The researchers tested the watch data against measurements from the COSMED K5 metabolic analyzer to determine which watch was the most accurate in tracking calories.<\/p>\n<p>Apple was the most accurate, while Garmin and Samsung overestimated calories burned the most, the university said.<\/p>\n<p><img decoding=\"async\" width=\"665\" height=\"443\" loading=\"lazy\" src=\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/09\/Low-Res_FIU-Smartwatch-Calorie-Accuracy-Study-Jason-Kostrna-4.jpeg\" alt=\"FIU researcher Jason Kostrna, wears the four smartwatches tested in his study. The watches include the Apple Watch Series 8, Fitbit Sense 2, Samsung Galaxy Watch 5 and Garmin Forerunner 955 (Taimy Alvarez\/Florida International University)\"\/><\/p>\n<p>Sometimes Google\u2019s Fitbit failed to generate a reading at all or reported incredibly low and implausible counts. <\/p>\n<p>The jury is still out on the watch\u2019s accuracy because a lot of that data was excluded from the study.<\/p>\n<p>The Independent has reached out to the watchmakers for comment on the findings. <\/p>\n<p>It\u2019s unclear why the researchers found the watches disproportionately struggled to record calories for people with higher body fat.<\/p>\n<p>Kostrna theorized the algorithms the watches use to estimate calories burned may play a role.<\/p>\n<p>&#8220;When the companies are developing those algorithms, we don\u2019t know where the test data is coming from,&#8221; he said. &#8220;That&#8217;s why I think it&#8217;s beneficial for the companies to see this type of data, so they can refine their products over time.&#8221;<\/p>\n<p><img decoding=\"async\" width=\"665\" height=\"443\" loading=\"lazy\" src=\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/09\/GettyImages-1421721322.jpeg\" alt=\"A new Apple Watch Series 8 is displayed during an Apple special event in Cupertino, California, in September 2022. The researchers say smartwatches can still be useful to wearers, even with limitations (Getty Images)\"\/><\/p>\n<p>However, the researchers stressed that the watches can still be useful to wearers &#8211; even with limitations.<\/p>\n<p>They may be imperfect, but the devices can \u201cstill have an important role to play\u201d in tracking one\u2019s health, Kostrna said. <\/p>\n<p>The next phase of the university and Kostrna\u2019s research will look at how the watches estimate calories during strength training workouts.<\/p>\n","protected":false},"excerpt":{"rendered":"Your smartwatch may not be telling you the truth about the calories you burn in a workout &#8211;&hellip;\n","protected":false},"author":2,"featured_media":591532,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[356,111,139,69,145],"class_list":["post-591531","post","type-post","status-publish","format-standard","has-post-thumbnail","category-gadgets","tag-gadgets","tag-new-zealand","tag-newzealand","tag-nz","tag-technology"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/591531","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=591531"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/591531\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/591532"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=591531"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=591531"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=591531"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}