This is a question I have been asking for some time. For sufferers of exfoliative cheilitis, they will know that constant in contact with water will make those thicker skin on your lips get a bit looser and finally come off easily. You will then end up with rawer but usual underlying lips texture.
I have avoided swimming for some years during my exfoliative cheilitis condition being more severe like when having a secondary infection. But now I think if swimming gives you enjoyment and it’s an exercise that you truly enjoy, why not just go for it. You may want to apply a thick layer of your usual lip balm (be it vaseline, aquaphor or cerave healing ointment) before heading to the water.
After the swimming session, I will use some normal saline to lightly rinse my lips and quickly apply my usual lip balm again. I personally don’t see swimming will worsen the peeling. Some may think that this actually provides a great opportunity to actually moisturize your lips from where it’s needed.