A ounce of perception is worth a pound of  performance, or so the saying goes.  And according to the 2008 Harvard study of a small group of hotel housekeepers it would seem to be so. We have all seen hotel maids lugging heavy equipment around hotel corridors, yet those who participated in the study claimed never to exercise. And to add to the disconnect, given the amount of exercise these maids actually participated in on a daily basis, their body-fat, blood pressure, weight and  body mass index matched their perception of how little exercise they undertook.  Curiouser and curiouser. The housekeepers were split into two groups, one group being told that their daily activity met the surgeon general’s definition of an active lifestyle, and the other told nothing at all. A month goes by and the research team return to retake the physical measurements and surprise surprise.  The group that…