A few years ago I became a runner. This has helped me so much as a writer.
I am not a gazelle who is going to win prizes or running shoe endorsements so running give me time to think about things that I am writing about. I think a lot about how to solve problems in my writing when I am running.
Since I finish races in twice the time as people who finish first I obviously run for different reasons. But this not coming in first all the time, well ever, has taught me self acceptance. Before I started running I would write in fits and starts and I would submit my work and it would get rejected and I would think that meant I wasn't a writer. Not winning races does not make me less of a runner just as not having my work in a book or magazine doesn't make me any less of a writer. Although it would be really cool to have a book published.
Groups are very helpful for both things. My running group pushes me to be a better runner. Those ladies push me to run farther and faster than I would on my own. My writing group does the same thing for my writing. It is so great to be connected to both groups.
Running is something you have to do on a regular basis if you want to be good at it. This is true of writing as well. No one would expect to run a long distance without first training for it. You run, you train and you work up to the distance. Most people do not wake up and say "I think I'll run 10 miles today" without having done some running before. The same is true for writing. It is something that needs time and practice and the more I work at it and make time for writing the better I get.
They both take commitment. There is always something that would be better than running 5 miles or writing 5 pages but once I do it I can cross it off my list of things to do and go about my day feeling accomplished.