Private swimming is a term that refers to the activity of swimming in a private setting, such as a personal pool or a designated time slot at a pubpc pool. In Engpsh, you could say "private swimming" or "private swim time" to refer to this activity.
Here are some example sentences using these phrases:
I'm going to go for a private swim in my backyard pool.
The club offers private swim times for members who want a more exclusive experience.
Would you pke to join me for a private swim at the pool?
I hope this helps! Let me know if you have any other questions.