I've been reading up on dealing with stress and maintaining mental health, and exercise comes up as the number one solution. Scientists believe our hunter-gatherer ancestors walked at least five kilometres a day, and that, clearly, is not a feature or modern life.In thinking about Brett Victor's amazing talk, "The Humane Representation of Thought" ( http://worrydream.com/#!/TheHumaneRepresentationOfThoughtTalk ), I was wondering: what is the cutting edge of doing knowledge work while not being stationary all day long?