Q: Apply Watch Calorie Count

Hi

When you record a workout using the built-in Workout app, Apple Watch has access to additional data when estimating the results of your activity, including calories burned.

When using the Workout app, Apple Watch uses the built-in heart rate sensor to measure your heart rate continuously. If you take your iPhone with you during an Outdoor Walk workout, it can also access data from your iPhone to help estimate your pace and distance. This may include GPS data (if Location Services is enabled) and/or data from the iPhone motion coprocessor (depending on model).

When tracking the same activity without using the Workout app, your watch will not use the heart rate sensor. The Activity app places greater reliance on data from your arm motion (measured by the built-in accelerometer) to estimate pace and distance.

When using only the Activity app (which operates continuously in the background), for the best tracking results, it will help to allow your arm to swing naturally whenever you are walking or running.

Calibration can help to improve the accuracy of various estimates made by both the Activity app and Workout app.

More information:

Use the Workout app on your Apple Watch - Apple Support

Use the Activity app on your Apple Watch - Apple Support

Calibrating your Apple Watch for improved Workout and Activity accuracy - Apple Support