nscrbug, The new Garmin uses Prediction of functional aerobic capacity without exercise testing as one of the parameters to calculate your calories, make sure that your "Activity Class" is set up correctly on your device profile, also the gender, age, weight and height values have to be correct as this would cause a low or high calorie values depending on the activity class setting. You may have to change the Activity Class settings in order to get more accurate calorie count reading.