WHY DO THIS?
Two IMPORTANT points:
1) There is no exercice or training method which makes our body burn fat from one especific part of our body:
When a body’s muscle is starting to do an effort which burns fat, that muscle (or muscles if you move more than one) ask for fat, then the body, depending on its gens, chooses where the fat is taken from.
That is the reason why everyone gets and loses weight in a different way:
2) By moving only one single muscle is really difficult to burn the necessary fat in order to lose weight.