Fitness trackers do not measure well energy expenditure

This study tested the accuracy of consumer fitness trackers in 30 adults (15 men, 15 women). Participants wore four different devices—two on each wrist—while their actual calorie burn was measured using professional laboratory equipment. The results showed that most consumer devices underestimated calorie expenditure, and the errors got worse as people burned more calories throughout the day. The difference between the least accurate device (Microsoft Band) and the most accurate (Apple Watch) was over 750 calories per day—a significant discrepancy that could mislead people trying to manage their weight or fitness goals.

This is a qualitative review study and it is highly affected by the independent analyses that are being reviewed. We will add the studies used in this review to evaluate independently each of them.