Poet's Walk, Central Park. Photography by Henri Silberman.
I know writer's can believe themselves to be nonathletic or just plain lazy. But casual exercise, like walking, on a daily basis is very important. Besides being good for your health physically, it provides intellectual freshness as well. Sometimes, when we are stuck with an idea or want to brainstorm a plot, taking a walk is a marvelous way to ponder over concepts. Walking can be a great way to forget about your writing, too. Sometimes writer's need to time to think of nothing at all - to let their mind rest from the pull of their stories.
Here is a famous essay by Thoreau on the subject of walking for your inspiration:
http://ecotopia.org/walking/
