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# addWorkoutActivity(_:completion:)

Adds a workout activity to the workout builder.

```
func addWorkoutActivity(_ workoutActivity: HKWorkoutActivity, completion: @escaping @Sendable (Bool, (any Error)?) -> Void)
```

```
func addWorkoutActivity(_ workoutActivity: HKWorkoutActivity) async throws
```

## Parameters

`workoutActivity`

The workout activity to add.

`completion`

A callback handler that the system calls after adding the workout activity. The system calls the callback handler on an anonymous background queue.

    The callback handler takes the following parameters:

- success: Contains <doc://com.apple.documentation/documentation/Swift/true> if the builder successfully added the activity.
- error: If the `success` parameter is <doc://com.apple.documentation/documentation/Swift/false>, this parameter contains information about the error; otherwise, it’s `nil`.

## Discussion

You can call this method repeatedly to incrementally add activities to the builder. Calling this method after calling [`finishWorkout(completion:)`](/documentation/HealthKit/HKWorkoutBuilder/finishWorkout(completion:)) fails with an error.

If you add an [`HKWorkoutActivity`](/documentation/HealthKit/HKWorkoutActivity) object that doesn’t have an [`endDate`](/documentation/HealthKit/HKWorkoutActivity/endDate), you can set the end date by calling [`updateActivity(uuid:end:completion:)`](/documentation/HealthKit/HKWorkoutBuilder/updateActivity(uuid:end:completion:)).

---

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