How to edit workouts

You can delete a workout from the health app or the fitness app.

Though you can not modify either.

You can't add a workout in the fitness app, but you can in the heath app.

To add in the health app.

Open the app

Open the workouts

Tap Add Data

modify your data, tap add

To delete in the health app.

Open the app

Open the workouts

scroll down and tap "Show All Data"

Tap Edit

Then tap the - beside the workout you want to delete

In the fitness app

On the line that says "workouts" on the right of that it shows "Show More" tap this

find the workout you want to delete and swipe left on it, then tap delete

modify your data, tap add

Workouts can be added,deleted and edited in the phone's health app.

What exactly are you trying to edit?

Maybe then someone can give you the proper steps.