I regularly do a kettleworx workout. How best do I describe this to my watch?
Apple Watch series 2
Hi
When recording workouts via the Workout app, choose the activity type that most closely matches your workout. This enables your watch to use the most appropriate sensors and data sources when estimating results, including using tailored calorie calculations for the main, pre-set activity types.
To record workouts that are neither included within nor sufficiently similar to those in the main list, such as your kettleworx workouts, choose "Other" as the activity type.
This credits one minute of Exercise for each full minute of the workout and Active Calories (Move goal) at a rate equivalent to a brisk walk or based on data from the heart rate sensor, whichever is higher.
When ending your Other workout, tapping the option to "Name Workout" will enable you to label the workout from a range of activity types, which include Strength Training.
The workouts that you do most often will be added as Quick Start options in the Workout app, including Other workouts with their previously saved names.
More information:
Work out with your Apple Watch - Apple Support