The Apple Watch Workout app offers an option to "Save" a workout when it has been completed. Where are such saved workouts saved?
The Activity app on your iPhone has it (iOS 10 & watchOS 3).
- Open Activity on your iPhone
- Browse to the day
- Hit workouts at the bottom
- Select the workout
For my Indoor Run, it has the type, time, active & total calories, distance, total time, average heart rate and average pace (also split out by mile). Doesn't have maximum heart rate, though.