The assertion "The answer seems to be frequent and repetitious movement, for at least 30 minutes" is made but you need to buy the ebook if you want to know why. Seems like an advertisement.
Shame on me for including a link to my book at the bottom of the article. SHAME ON ME!
Don't think I'll be buying the book. In any given week I have about about four stretches of continuous motion, either running or walking, last between 50 and 90 minutes. It is very seldom that I get the "can run forever" feeling that I sometimes got as younger, leaner, fitter man.