The HKActivitySummaryType class is a concrete subclass of the HKObjectType class. To create an activity summary type instance, use the object type’s activitySummaryType() convenience method.
You only use activity summary types to request permission to read HKActivitySummary objects from the HealthKit store. To query for activity summary objects, use an HKActivitySummaryQuery. You can also create your own HKActivitySummary objects (for example, to display in an HKActivityRingView), but you cannot save them to the HealthKit store. However, any workouts that you save to the HealthKit store may affect that day’s summary. For more information, see Filling the Rings.
Using Activity Summary Types
Like many HealthKit classes, activity summary types are not extensible and should not be subclassed.