Someone told me the other day that they found swimming too boring, but that's part of its attraction for me when I'm writing.
In my opinion it's the perfect form of exercise for any writer.
Charles Dickens walked for miles all over London, often at night. I like walking, especially since I discovered the Waterlink Way, but it's often too distracting and not something for after dark. When I worked in China, where it was -25C for three months in Winter, the company had a mini-gym with a treadmill. But I frequently fell off it because you had to concentrate to keep at the right pace.
Swimming activates the brain in the same way as walking but you don't have to worry about the weather or where you put your feet. I can just think about the story I'm writing or work out a new plot as I go back and forth. Afterwards I sit in the café for a while and study some magazines. On my first visit to the new pool I bought food and drink but now I take my own sandwich, as I used to at the Ladywell baths.
It can be inspiring, too. Often, I like to swim with my head up to see what's happening. There was a mad woman in the first week who jumped in but couldn't swim and the attendant shouted to her to grab the end of a pole. Last year at another pool my husband, who favours a back-crawl, bumped into a poor swimmer. The attendant set off an alarm to clear the pool. Maybe it's a coincidence, but the first short story I sold to a magazine was set in a swimming baths. It was about a young man's first day as a trainee instructor and was titled 'In at the Deep End'!