I see this all the time outside of Ironman training. There's a cliche that goes something like, "If you want something done, ask a busy person." They are in motion, therefore easily maintain that motion. Have you ever tried to get a couch potato off the couch? They are displaying uniform motion (zero), and the external force needed to change that is massive.
Sometimes I just need to find that motivation to overcome inertia. But when I look for it, I find it. Of course, that leads to Newton's Third Law, where every action has an equal and opposite reaction. Riding my bike (action) leads to more laundry (reaction). Dang that Newton anyway.