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- May 10, 2012
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Not fit for purpose: Fitness trackers are so inaccurate with calorie counting they are getting readings wrong by 40 per cent, study reveals
Researchers have found that fitness trackers are so inaccurate with their calorie counting, they are getting readings wrong by up to 40 per cent.
A new study has revealed that trackers made by Fitbit and Jawbone underestimated the calorie burn for household chores and notably overestimated it during vigorous exercise.
In a review of two wrist worn and two hip-worn trackers, readings were accurate enough with 'sedentary exercise' - but overestimates ranged from 16 to 40 per cent for anything more strenuous..
Researchers found in a study of four trackers that included the Fitbit One (left) and the Fitbit Flex (right) they overestimated calorie burn during vigorous exercise by up to 40 per cent
The news of inaccurate readings comes as three law suits have been filed against Fitbit, claiming its heart trackers are 'inaccurate'.
In the study researchers from Ball Sate University tested two wrist-worn trackers - the Fitbit Flex and Jawbone UP24, and two hip-worn trackers, the Fitbit Zip and Fitbit One - on 30 adult participants of different ages and fitness levels.
The members lay on a bed for ten minutes and then exercised for five minutes at a time while a metabolic analyser measured their calorie loss.
for exercises classed as 'sedentary', all four trackers were accurate to within eight per cent of the analyser's calorie count.
But for exercises that simulated household work, all the trackers except the Fitbit Flex underestimated calorie output by 27 to 34 per cent.
And during strenuous exercise, none of the trackers were accurate in their readings - with overestimates ranging from 16 to 40 per cent.
Fitbit, the most popular brand of tracker, sold 21.4million devices of the 115million trackers sold around the world last year, according to the research company Gartner.
In the study researchers from Ball Sate University tested two wrist-worn trackers - the Fitbit Flex and Jawbone UP24 (pictured), and two hip-worn trackers, the Fitbit Zip and Fitbit One - on 30 adult participants of different ages and fitness levels
Alexander Montoye, a study researcher, revealed that they decided to do the tests to find out how well trackers actually worked since they first became popular in 2013.
He told The Times: 'We found irregularities in several areas but still, for a lot of people, fitness trackers can be a great motivational tool.'
A Fitbit spokesman claimed their trackers are 'not intended to be scientific or medical devices' and are instead designed to 'provide meaningful data'.
A spokesman for Jawbone called the UP24 a 'relatively old product' which used 'older technology'.
The news comes as a class-action lawsuit slammed Fitbit devices, specifically Surge and Charge HR, for being 'highly inaccurate', which was highlighted in a recent study conducted specifically for the case.
Researchers found the PurePulse monitor in the devices is off by up to 20 beats per minute after comparing results with a Zephyr Bioharness – but Fitbit told DailyMail.com that 'the study is flawed'.
THE LAWSUIT AGAINST FITBIT
Three people, including Kate McLellan are suing the company, claiming Fitbit's heart rate monitor does not work.
Speaking to NBC News, Ms McLellan said: '[Fitbit] made it seem like it was my fault, like I was using it wrong, and said it's not meant to track your heart rate all of the time.'
However, Fitbit believes that the case does not have merit.
They have stressed that their trackers are designed to provide meaningful data to help users reach their health and fitness goals and are not scientific or medical devices.
'The study is very flawed, as it compares the Fitbit devices with the Zephyr,' a source close to Fitbit told DailyMail.com.
'Researchers give the implication that the zephyr used to conduct the study has been proven and validated, but it hasn't.'
'There isn't a gold standard device that can be accurately compared to Fitbit.'
The lawsuit was filed earlier this year by individuals who bought the devices to help the track their heart rate, some because it was suggested by a doctor due to medical history and opted in to buy one of the more expensive models.
'Our claim is that Fitbit knowingly marketed and sold devices equipped with the PurePulse technology that do not in fact accurately measure heart rates during the very types of moderate to intense exercise Fitbit shows people doing in its ads,' Jonathan Selbin, partner at Lieff Cabraser Heimann & Bernstein in New York City and one of the attorneys who filed the lawsuit, told DailyMail.com.
The study was performed by researchers from California State Polytechnic University.
They tested the heart rates of 43 healthy adults using Fitbit's PurePulse heart rate monitors, as well as a consumer-grade ECG device.
Researchers found that Fitbit's devices can be off by up to 20 beats per minute during intensive workouts, after comparing results with a Zephyr Bioharness.
- Researchers did a study on three Fitbit devices and one Jawbone tracker
- Some underestimated calorie burn up to 34 per cent for household chores
- And with strenuous activity they overestimated by 16 to 40 per cent
Researchers have found that fitness trackers are so inaccurate with their calorie counting, they are getting readings wrong by up to 40 per cent.
A new study has revealed that trackers made by Fitbit and Jawbone underestimated the calorie burn for household chores and notably overestimated it during vigorous exercise.
In a review of two wrist worn and two hip-worn trackers, readings were accurate enough with 'sedentary exercise' - but overestimates ranged from 16 to 40 per cent for anything more strenuous..
Researchers found in a study of four trackers that included the Fitbit One (left) and the Fitbit Flex (right) they overestimated calorie burn during vigorous exercise by up to 40 per cent
The news of inaccurate readings comes as three law suits have been filed against Fitbit, claiming its heart trackers are 'inaccurate'.
In the study researchers from Ball Sate University tested two wrist-worn trackers - the Fitbit Flex and Jawbone UP24, and two hip-worn trackers, the Fitbit Zip and Fitbit One - on 30 adult participants of different ages and fitness levels.
The members lay on a bed for ten minutes and then exercised for five minutes at a time while a metabolic analyser measured their calorie loss.
for exercises classed as 'sedentary', all four trackers were accurate to within eight per cent of the analyser's calorie count.
But for exercises that simulated household work, all the trackers except the Fitbit Flex underestimated calorie output by 27 to 34 per cent.
And during strenuous exercise, none of the trackers were accurate in their readings - with overestimates ranging from 16 to 40 per cent.
Fitbit, the most popular brand of tracker, sold 21.4million devices of the 115million trackers sold around the world last year, according to the research company Gartner.
In the study researchers from Ball Sate University tested two wrist-worn trackers - the Fitbit Flex and Jawbone UP24 (pictured), and two hip-worn trackers, the Fitbit Zip and Fitbit One - on 30 adult participants of different ages and fitness levels
Alexander Montoye, a study researcher, revealed that they decided to do the tests to find out how well trackers actually worked since they first became popular in 2013.
He told The Times: 'We found irregularities in several areas but still, for a lot of people, fitness trackers can be a great motivational tool.'
A Fitbit spokesman claimed their trackers are 'not intended to be scientific or medical devices' and are instead designed to 'provide meaningful data'.
A spokesman for Jawbone called the UP24 a 'relatively old product' which used 'older technology'.
The news comes as a class-action lawsuit slammed Fitbit devices, specifically Surge and Charge HR, for being 'highly inaccurate', which was highlighted in a recent study conducted specifically for the case.
Researchers found the PurePulse monitor in the devices is off by up to 20 beats per minute after comparing results with a Zephyr Bioharness – but Fitbit told DailyMail.com that 'the study is flawed'.
THE LAWSUIT AGAINST FITBIT
Three people, including Kate McLellan are suing the company, claiming Fitbit's heart rate monitor does not work.
Speaking to NBC News, Ms McLellan said: '[Fitbit] made it seem like it was my fault, like I was using it wrong, and said it's not meant to track your heart rate all of the time.'
However, Fitbit believes that the case does not have merit.
They have stressed that their trackers are designed to provide meaningful data to help users reach their health and fitness goals and are not scientific or medical devices.
'The study is very flawed, as it compares the Fitbit devices with the Zephyr,' a source close to Fitbit told DailyMail.com.
'Researchers give the implication that the zephyr used to conduct the study has been proven and validated, but it hasn't.'
'There isn't a gold standard device that can be accurately compared to Fitbit.'
The lawsuit was filed earlier this year by individuals who bought the devices to help the track their heart rate, some because it was suggested by a doctor due to medical history and opted in to buy one of the more expensive models.
'Our claim is that Fitbit knowingly marketed and sold devices equipped with the PurePulse technology that do not in fact accurately measure heart rates during the very types of moderate to intense exercise Fitbit shows people doing in its ads,' Jonathan Selbin, partner at Lieff Cabraser Heimann & Bernstein in New York City and one of the attorneys who filed the lawsuit, told DailyMail.com.
The study was performed by researchers from California State Polytechnic University.
They tested the heart rates of 43 healthy adults using Fitbit's PurePulse heart rate monitors, as well as a consumer-grade ECG device.
Researchers found that Fitbit's devices can be off by up to 20 beats per minute during intensive workouts, after comparing results with a Zephyr Bioharness.
