Your Smartwatch Could Be Lying About Your Workout

Key Points:

• A study from Florida International University found that popular fitness trackers like the Apple Watch Series 8, Fitbit Sense 2, Samsung Galaxy Watch 5, and Garmin Forerunner 955 can overestimate calorie burn during exercise by 15% to 25% or more.
• Apple Watch was the most accurate, while Garmin and Samsung tended to overestimate calories burned, and Fitbit showed inconsistent and sometimes faulty readings during testing.
• The study involved 58 adults cycling on stationary bikes with energy expenditure measured by clinical-grade equipment, revealing less accuracy in calorie estimates for participants with higher body fat percentages.
• Despite inaccuracies in calorie counts, smartwatches remain useful for tracking heart rate, workout duration, and fitness trends over time, but users should treat calorie burn figures as rough estimates rather than precise data.
• Researchers caution against relying heavily on calorie counts for weight management, as overestimations could lead to unintended overeating if users reward themselves based on inaccurate numbers.