

There are two different mechanisms here:  toning of muscles and reduction of
fat.  Exercises specific to particular muscles will tone only those muscles
exercised (example: look at differences in arm circumferences between pitching
arms and non-pitching arms in major league pitchers).  However, if exercise
also leads to reduction of body fat, the loss of body fat will be equally
distributed over the entire body.  There is no way to "spot reduce" body fat
other than surgically, through liposuction. Distribution of body fat is
genetically determined.  Sometimes a very flabby muscle will look like "fat",
so when that muscle gains some muscle tone it may *appear* as though the "fat"
is "changing" into "muscle", but really fat and muscle tissues are totally
separate, and one does not ever "change into" the other.
