... [T]he working memory performance of both age groups improved when walking at their chosen speed compared with when sitting or walking at a fixed speed set by the researchers. This was especially the case for more difficult versions of the working memory task, and was more pronounced among the children than the adults. So, this would appear to be clear case of mental performance actually being superior in a dual-task situation.This was hardly a new idea by the time Nietzsche expressed it in bombast -- Aristotle's peripatetic school linked walking and thinking way back at the very founding of western philosophy, Thoreau wrote extensively about it, and Nietzsche's contemporary, Charles Darwin, famously preserved his mind and body with daily walks along his sandwalk.
I add my anecdotal evidence that the same benefits apply to running, which falls under the same principle of "chosen speed" for those of us who do it. I have long noted that running liberates my thinking as nothing else does, and that overcoming a mental impasse calls for moving my body in a free, unstructured way. This works whether I am seeking it or not -- I frequently jot down notes to myself immediately after a run since I know the thoughts will dissipate a short while after I sit down. I had attributed this to the relative wakefulness I achieve while running -- it's as far from narcoleptic-sleepy as I ever get -- but this research suggests a slightly different dynamic. Then again, maybe greater wakefulness and sharper cognition come to the same thing.
It has now overcome mere maxim, strolled past common sense, and approached the precincts of scientific fact: if you want to think clearly, get up and walk at your own chosen speed.
(via Norm Geras)