Smartwatches Overestimate Calorie Burn by Up to 25%, Study Finds
A new study indicates that smartwatches may significantly overestimate the number of calories burned during exercise, with error rates ranging from 15% to 25%. The research, published in PLOS One, analyzed data from smartwatches across four major brands: Apple, Garmin, Samsung, and Fitbit. Participants cycled on a recumbent bike while wearing these devices, and their actual energy expenditure was measured using laboratory equipment that analyzes gases in breath. The study found that all devices provided inaccurate estimates, though the degree of inaccuracy varied by brand. Apple watches were found to be the most accurate, while Garmin and Samsung tended to overestimate calorie burn. Fitbit exhibited the largest variability and occasional missing data. The error rate was observed to increase with participants' body fat percentage, though skin tone did not appear to be a factor in this specific study. Experts attribute these inaccuracies to the reliance on proprietary algorithms that translate signals like m...
