The idea upon which this is based is called hormesis. See: http://en.wikipedia.org/wiki/Hormesis http://en.wikipedia.org/wiki/Hormesis http://en.wikipedia.org

The idea upon which this is based is called hormesis. See: http://en.wikipedia.org/wiki/Hormesis http://en.wikipedia.org/wiki/Hormesis http://en.wikipedia.org/wiki/Radiation_hormesis http://en.wikipedia.org/wiki/Radiation_hormesis http://en.wikipedia.org/wiki/Caloric_restriction http://en.wikipedia.org/wiki/Caloric_restriction The basic idea is that our ancestors were under stress so often that we evolved beneficial processes that kick in during times of stress, and only times of stress. Without the right environmental cues our bodies won't do the right thing. Imagine having to red-line your car for a few seconds in order to start the automatic oil-change.