Fitness watches have been found to consistently overestimate calories burned during workouts. A study tested devices from Apple, Garmin, Samsung, and Fitbit against clinical lab equipment. The results showed error rates ranging from 15 to 25 percent.

The study compared the accuracy of various devices, finding that Apple was the most accurate, while Garmin and Samsung overestimated the most.

Further details on the study's findings are available, including the potential impact of relying on these estimates for calorie tracking and overall health.