If you have noticed that the calories earned for your workouts are lower in the app after saving your workout than they appeared in the app during your workout. Generally this can be attributed to the difference between TOTAL and ACTIVE calories.
Total Calories vs Active Calories
Your TOTAL calories represents the amount of energy your body uses over the course of a workout, but this also includes the calories that you would have burned had you been completely at rest for the duration of your workout.
For example, if your body burns a total of 75 calories every hour just to live (to perform basic functions like breathing, thinking, and digesting) and you burn an additional 125 calories through activity for that hour then your total calorie burn for that hour-long workout would be 200 calories.
Your ACTIVE calories for a workout include only the calories that you burned specifically for the workout, subtracting the calories that you would have burned at rest. For the example above your ACTIVE CALORIES would only be 125, as opposed to 200.
How can I change this setting?
Apple Health and nutrition apps like MyFitnessPal only accept ACTIVE CALORIES, as transferring TOTAL CALORIES would cause a number of those calories to be counted twice.
You can select whether to display TOTAL CALORIES or ACTIVE CALORIES in the app by tapping the metric and selecting to display ACTIVE CALORIES instead. If you are using a nutrition-tracking app or are looking to burn a specific number of calories during your workout it is generally better to display ACTIVE CALORIES as this will be more accurate.