Dara,
What a great idea. You relieve stress by swimming and at the same time you are getting wonderful exercise and time to think while you are alone. Any type of strenuous exercise does relieve stress. Just make sure it is something that you enjoy doing. For instance, some people run their stress off. I absolutely hate to run but I love to swim so I can swim and be happy. It is not work or the dreaded exercise for me. Running or walking on the treadmill is exercise so I don't like it at all.
I love the idea of time to think while you are swimming. I never have time to think about important things. My kids or the phone always interrupt my thinking time. It is great that you have a setup where you can be alone for a time. I wish I had that but no one ever leaves me alone at my house. Thank you for sharing.