This is part of being a Personal Trainer. These people see us as someone who they feel free to talk to and “unload” what ever bothers them. We are also part psychologists and if you really want to be successful in this business than listening is a big part of the it. So depending on the client you’ll have to take it case by case. There is always a way to work both in (training and carrying a conversation).
A few of my clients talk the entire session. I listen and let them talk as much as they want. It was a little hard at first (years ago) to keep up with their conversation and keep my mind on their workout. But now it is no problem. I actually find it a nice relief from clients that expect me to talk and keep them entertained/distracted/in the moment/etc. And for many of them, it seems to relieve their stress from their lives, work, families, etc.
But if that isn’t your client fit, I would consider referring them to another trainer. If you don’t like the talkative client, it will wear on you. Or you could try to enjoy it from another viewpoint.
Just read your last comment about the only time she compromises safety and correctness (and the goal)…. One guess is your client may be talking to get out of a difficult portion of her workout. Another strategy for you would be to sit down with her and reevaluate her goals and what her–and your–expectations are for the sessions.
She may have given you a goal to achieve, but perhaps she is not ready for the work it entails.
I would ask my client-PRIOR to the workout.. to “please focus on your workout as it’s crucial to stay focused. AND as you trainer it’s my job is to insure a safe, correct, workout with your goal/safety first and foremost in mind. If I feel you need to stop talking and re focus I’ll let you know during our session.
Are you ok with this?”
I have asked my clients to stop talking during crucial exercises/times. It can be said in a nice manner, a caring manner. To this day they are all still training with me! It shows you are a pro and really care about their results