A body at rest tends to stay at rest and a body in motion tends to stay in motion unless something or someone acted upon by external forces. That is Newton's law of inertia and momentum. A rock stays motionless unless something or someone forces it from its resting position. When it comes to humans beings, the force that can move us comes from our minds that force is our motivation.
When I came up with the name Bodies in Motion for my exercise program, I was thinking about how we are all a part of the universe and that the universe is in motion. Look around you planets, stars and galaxies are all in motion and living things are in motion, too.