I have solid proof that walking helps writing. The two topics may seem completely unrelated, but they are not.
Whenever I am stuck while writing a scene or chapter, I just need to get out of the chair and walk about the house. Walking out in the open is even better. Just stand up and work your legs. Walk. Continue.
The results will show immediately. Ideas would flow and you'd have to go back to the table to jot them down, so you won't lose them. That's the way it works. When the blood travels away from the head to the feet, it works wonders.
These are nitty-gritties of the writing life that are so significant that they're not noticed until ideas stop flowing. Outdoor life, without losing focus, can be a great inspiration. A walk in the neighborhood park is beneficial. So is a little outing on your bicycle, when you let the breeze touch you as well as your inner self.
Writing is a constant balancing of energies and thoughts, and that can be achieved with a minute eye for one's body and mind.