“We should take wandering outdoor walks, so that the mind might be nourished and refreshed by the open air and deep breathing.”
Seneca, On Tranquility of Mind.
In the same way that a ‘refresh’ of your computer screen might reload a web page or synchronise your email inbox with new emails (by the way, whether you want the emails or not, your inquisitive mind is already distracting you from whatever else you could be doing), so going for a walk ‘refreshes’ the super-computer inside your skull.
Even a short walk can introduce new random stimuli to your mind, allowing it to let go of whatever it is currently fixated on. It is important, however, that you take notice of what is here, now – and not simply walk in a zombie trance, engulfed in the same thoughts that were occupying you. Take notice! Look deeply! Wander and wonder.