Here's how silent walking improved my health, and why walking without distraction can boost mental well-being.

Just some time alone with your thoughts ... But not just any walk: a silent one. For her, the 30-minute stroll was revelatory. No podcasts, no music. Just “me, myself and I.” ...

(The memos have been known to reach up to six pages, and the silent start may last as long as 30 minutes.) During this time, moderator and attendees peruse. They scribble notes in the margins.