I was walking along with J.R. and K.M. when I mentioned the well studied and scientifically proven theory I invented called the Heart Beat Theory :) I invented this theory to justify why I don't run for exercise (or exercise too much).
Heart Beat Theory: Each individual has a predetermined number of heartbeats in their life - consequently you need to be sure to conserve your heart beats.
Note that exercising by running would use too many heartbeats and thereby reduce your elapsed time for life. In describing this theory, many have countered that runners (who during their runs have overexercised their heart beats) have such low pulse rates (hence conserving heart beats during the day to day activities). They use this argument to convince me that running is a great way to exercise.
However there is a corollary to the Heart Beat Theory to combat this attempt to get me to exercise by running.
Corollary 1: "Wide fluctuations in rates of heart beats are also dangerous to one's health."
As the theory progresses in science there will be many other corollaries developed. But for now - keep the heart beats moderately moving :)
PS. You can use the Heart Beat Theory for other justifications - like napping :)