When you connect to the Apple Watch App and complete a workout or cardio activity, you get to view real-time data right from your wrist.
You can see the amount of calories burned, time or distance targets, heart rate data, including heart rate and heart rate zone. All of this data will also be recorded within the app, allowing you to look back on your performance.
For workouts: As you complete each exercise there will be an accompanying tracker to both guide and record your progress. Depending on the exercise, it will count down the time if it is a timed exercise, have a stopwatch for a cardio exercise, or you can enter reps/weights, etc if it is a text target exercise.