Study Shows Wearable Devices Vary in Accuracy for Fitness Metrics

Wearable fitness devices like Apple Watches are widely popular for tracking daily activity, heart rate, calorie burn, and other health metrics. However, recent research from the University of Mississippi reveals that the accuracy of these devices varies depending on the type of data measured and the user's activity. Professor Minsoo Kang and doctoral student Ju-Pil Choe conducted a comprehensive review of 56 studies comparing Apple Watch readings to trusted reference tools.

The findings highlight that Apple Watches are generally reliable when measuring heart rate and step counts, with mean absolute errors of 4.43% and 8.17%, respectively. Conversely, estimates of energy expenditure showed significantly higher errors, averaging nearly 28%. These inaccuracies were consistent across different user demographics and physical activities such as walking, running, cycling, and mixed workouts.

While the devices are useful for tracking basic activity and staying motivated, researchers emphasize they should not replace clinical assessments or medical advice. The study also indicates that newer Apple Watch models tend to be more accurate, reflecting ongoing technological improvements.

Experts advise consumers to view wearable data as helpful guides rather than definitive measurements. Healthcare providers and developers can use these insights to refine sensor technology and algorithms further, enhancing the reliability of wearable health devices.

The research was published in the journal Physiological Measurement and underscores the importance of understanding the limitations of consumer health tech products.