Assigning a User to a Profile grants them access to view and edit that Profile’s information. For example if you want multiple Trainers to be able to update a Client’s data, you’d assign multiple Trainers to that Profile.
In order to update a Trainer’s assignments, go to Users and click on the Trainer’s name.
The screen will now show you a list of Profiles assigned to that User.
Click on the Client’s name, and the Staff selector will appear. From there, just select which Trainers you’d like to have access to that Profile.