Calories are estimated based on the type of sport, your gender, your weight and the intensity and duration of the exercise.
Note: Not all activities are available on all watches.
For running, cycling, swimming or treadmill, the calorie calculations are based on metabolic equivalent of task tables (MET or simply metabolic equivalent).
We use the MET tables of Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett Jr DR, Tudor-Locke C, Greer JL, Vezina J, Whitt-Glover MC, Leon AS. 2011 Compendium of Physical Activities: a second update of codes and MET values. Medicine and Science in Sports and Exercise, 2011;43(8):1575-1581.
Calories for freestyle and gym activities are based on heart rate. For other activities calories are linked to that specific sport but for freestyle and gym, the watch doesn’t know which sport you are doing. Hence when no heart rate measurement is available, calories are not shown for freestyle and gym activities.
The calorie metric measures how many calories you burn during the day including your basal metabolic rate (BMR). Your BMR represents the minimum amount of energy that you need to keep your body functioning, including breathing and keeping your heart beating. Because BMR is included, your calorie metric in the tracker will be higher than your calorie metric in an activity.