It’s up to the client. When my clients attain their goals, I usually have a conversation with them and ask them if they have any new goals in mind. If clients have been compliant and pushed themselves to reach their goal(s), chances are they’ve grown to appreciate a good challenge and they’ll look forward to a new one. I try to give them some new ideas and if they express an interest in setting new goals, I perform another assessment and design a program that will help them reach those new goals. If not, I make sure they maintain their current fitness level until they decide what to do next. They may not have new goals in mind and may just want to maintain, which is a goal in itself. Clients who aren’t even willing to continue and train at a maintenance level may put their health and fitness on the back burner where it was before they began training, in which case you will likely hear from them again even if you’re parted ways.
The client usually knows what he/she wants, which takes a lot of pressure off me. If my clients are happy, then I’m happy too.