Do Smartwatches Measure Calories Accurately?
- Mar 30
- 5 min read
Updated: Apr 9
Smartwatches have become indispensable tools in daily life for tracking physical activity and health. The calorie (energy expenditure) data provided by these devices directly influences users' decisions, especially in areas such as exercise planning and weight management. However, the reliability of this data is often accepted without question.
Energy expenditure is a physiological parameter that is difficult to measure directly, and smartwatches estimate this value through algorithms that take into account variables such as heart rate, movement, and speed . This can lead to significant differences in accuracy between different devices and different activities.
This article examines how accurately three popular smartwatches can estimate energy expenditure during walking and running, comparing their results to the gold standard indirect calorimetry , based on a controlled study published in 2022. The aim is to scientifically determine the reliability of the calorie data provided by smartwatches and how this data should be interpreted for daily use.
