Your smartwatch may not lie to you about how many calories you burn when you exercise. But it’s almost certainly overstated, according to a revealing new study. Scientists asked 58 men and women of different ages and body weights to wear different smartwatches for the study, which was funded by the National Science Foundation. (The devices were manufactured by Apple, Garmin, Samsung and Fitbit.) Volunteers also donned high-tech face masks and other scientific paraphernalia to accurately measure metabolic changes.
