Does editing a routine change the routine?

Where you make the change decides. It is the same rule your plan follows.

• Open the routine and edit it there: the routine changes, and every workout you start from it after that uses the new version.
• Edit while you are logging: only the workout in front of you changes. The routine stays as it was.

So a session where you moved things around does not rewrite your routine. If you replaced an exercise while logging, the routine still holds the exercise you saved.

Learn more: If I change today's workout, does it stay changed?