Fitness bands undervalue your effort
Popular wrist-worn fitness monitors
underestimate energy expenditure with variances of more
than 40 per cent, University of Queensland researchers have
Supervised by Professor Jeff
Coombes of UQ's School of Human Movement
and Nutrition Sciences,
PhD student Matthew Wallen and collaborators tested four
"We determined the accuracy of the Apple Watch, Fitbit Charge
HR, Samsung Gear S and Mio Alpha," Mr Wallen said.
"None of the devices proved to be consistently more accurate
overall and the percentage error for energy expenditure was between
nine and 43 per cent.
"Measurement of heart rate was more accurate, with only minor
"Combining these two factors, it shows there are limits to how
much trust we can place in such devices to monitor energy balance
and, therefore, to serve as weight loss aids."
Testing involved 22 healthy volunteers (even split of males and
females) completing a variety of activities - ranging from running,
cycling and walking, to seated and laying rest - for a period of
approximately one hour.
The measurements of the wrist-worn devices were compared to
electrocardiography readings every 15 seconds and against a
portable gas analysis system which measured the number of calories
As per manufacturer instructions, each of the wrist-worn devices
was individualised to reflect the user's age, gender, height and
"We did seek technical assistance from each company to learn
information regarding the algorithms used by each device to
determine energy expenditure," Mr Wallen said.
"However, this information was not disclosed."
The research team noted that movement and folding of skin could
possibly cause reduced accuracy of wrist-worn fitness devices
during high-intensity or resistance-based exercise.
Other collaborators on the study were
Dr Shelley Keating and Dr Sjaan
Gomersall of UQ, and Professor Ulrik Wisloff of the
Norwegian University of Science and Technology.
Findings of the research have been published in the
Media: Matthew Wallen, firstname.lastname@example.org , +61
0419 183 401; Robert Burgin, UQ Communications, email@example.com
, +61 7 3346 3035, +61 448 410